From df63b036e391912880a587e60deb9a015c42dcbc Mon Sep 17 00:00:00 2001
From: Ali <010109ali@gmail.com>
Date: Tue, 14 Jul 2026 12:20:41 +0000
Subject: [PATCH] feat(sales-order): multi tax-article picker, mirroring Sales
 Invoice
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Sales Order had a single visible `tax_article` link field while Sales Invoice had
long since moved to a multi-select: several articles per item row, held in a
parent-level table and tied to the row by a generated key. The two had to match,
so Sales Order now gets the same picker — and the same exclusions.

Rather than copy 250 lines of dialog code into a second file that would drift,
the behaviour moves to item_tax_articles.js, which takes the doctype, the item
doctype, the child doctype, the table field and the row-key field as config.
sales_invoice_tax_articles.js and sales_order_tax_articles.js are now shims that
call .init() with their own config. Same split server-side: item_tax_articles.py
holds the validate logic, the two custom/*_tax_articles.py are entry points.

Sales Order keeps its own child DocType rather than reusing the invoice's. The
downstream consumers (VAT Allocation, the tax reports) anchor their joins on
`tabSales Invoice`, so sharing one table would be safe today — but a single future
query written without that join would pull sales orders into a filed tax return,
and that is not a trap worth leaving armed.

Articles ride into the invoice on conversion: get_mapped_doc only walks the
standard field map, so make_sales_invoice is wrapped to carry them across, matching
order rows to invoice rows via `so_detail`. Row keys are regenerated, not copied —
they are no_copy and the two documents key their rows independently.

`Sales Order Item.tax_article` becomes hidden/read-only/deprecated, exactly as on
Sales Invoice. Nothing referenced it (the table is empty), and vat_calculator.js —
which drove it, and which still serves any doctype using the plain link field —
now skips Sales Order the same way it already skipped Sales Invoice, so it no
longer clears a hidden field and dirties the form on every refresh.

The 302.6 / 302.6.1 exclusion added for Sales Invoice was reachable around: the
dialog filtered them out, but the collapsible "Item Tax Articles" table on the
parent let you pick them directly. Both child DocTypes now carry the same
`not like 302.6%` in link_filters, which is what guards that path.

Verified end-to-end against the live site (rolled back): an order with two articles
converts to an invoice that keeps both, under a fresh row key, surviving validate.
Both forms checked headless — shared module loads, cells render, legacy field
hidden, no JS errors, and Sales Invoice is unregressed by the refactor.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 jey_erp/custom/item_tax_articles.py           |  63 ++++
 jey_erp/custom/sales_invoice_tax_articles.py  |  66 +---
 jey_erp/custom/sales_order_tax_articles.py    |  77 +++++
 jey_erp/custom_fields.py                      |  44 ++-
 jey_erp/hooks.py                              |  15 +-
 .../sales_invoice_tax_article.json            |   2 +-
 .../sales_order_tax_article/__init__.py       |   0
 .../sales_order_tax_article.json              |  41 +++
 .../sales_order_tax_article.py                |   8 +
 jey_erp/patches.txt                           |   3 +-
 .../add_tax_articles_to_so_grid_views.py      |  56 ++++
 jey_erp/public/js/item_tax_articles.js        | 282 ++++++++++++++++++
 .../public/js/sales_invoice_tax_articles.js   | 244 +--------------
 jey_erp/public/js/sales_order_tax_articles.js |  19 ++
 jey_erp/public/js/vat_calculator.js           |  11 +-
 15 files changed, 636 insertions(+), 295 deletions(-)
 create mode 100644 jey_erp/custom/item_tax_articles.py
 create mode 100644 jey_erp/custom/sales_order_tax_articles.py
 create mode 100644 jey_erp/jey_erp/doctype/sales_order_tax_article/__init__.py
 create mode 100644 jey_erp/jey_erp/doctype/sales_order_tax_article/sales_order_tax_article.json
 create mode 100644 jey_erp/jey_erp/doctype/sales_order_tax_article/sales_order_tax_article.py
 create mode 100644 jey_erp/patches/add_tax_articles_to_so_grid_views.py
 create mode 100644 jey_erp/public/js/item_tax_articles.js
 create mode 100644 jey_erp/public/js/sales_order_tax_articles.js

diff --git a/jey_erp/custom/item_tax_articles.py b/jey_erp/custom/item_tax_articles.py
new file mode 100644
index 0000000..85dcd44
--- /dev/null
+++ b/jey_erp/custom/item_tax_articles.py
@@ -0,0 +1,63 @@
+# Multi tax-article per item row — shared server-side foundation.
+#
+# Source of truth for the (possibly multiple) tax articles of a line is a parent-level
+# table (Frappe has no nested child tables), whose rows point back at an item row by a
+# generated row key. Sales Invoice and Sales Order each have their own child DocType
+# and row-key field; everything else is identical, so the logic lives here once.
+#
+# The validate hook:
+#   1. guarantees every item row has a stable row key (so SQL joins from the item table
+#      to the article table are reliable),
+#   2. drops ONLY orphaned article rows (whose parent_row matches no item row) — the
+#      user's selection is otherwise kept regardless of tax template,
+#   3. refreshes the `custom_tax_articles_display` text (the grid cell summary).
+#
+# It deliberately does NOT write the legacy single `tax_article` field: the consumers
+# (VAT Allocation, tax reports) JOIN the child table, so that field is unused — and
+# writing it fought vat_calculator.js (which clears it on refresh for non-0% lines),
+# leaving the form perpetually dirty.
+
+import frappe
+
+DISPLAY_FIELD = "custom_tax_articles_display"
+TABLE_FIELD = "custom_item_tax_articles"
+
+
+def sync(doc, row_key_field):
+	"""Keep item rows, their row keys and their article rows consistent on save."""
+	# 1) ensure each item row has a unique, stable row key (links it to its articles)
+	seen = set()
+	for item in doc.get("items", []):
+		key = item.get(row_key_field)
+		if not key or key in seen:
+			key = "r" + frappe.generate_hash(length=10)
+			item.set(row_key_field, key)
+		seen.add(key)
+
+	# 2) keep every article row that points at a real item row; drop only orphans.
+	#    NOTE: we intentionally do NOT drop by item_tax_template — the user's selection
+	#    must survive saving even if the template is empty/non-0%.
+	item_keys = {item.get(row_key_field) for item in doc.get("items", [])}
+	rows = [
+		r
+		for r in (doc.get(TABLE_FIELD) or [])
+		if r.get("parent_row") in item_keys and r.get("tax_article")
+	]
+	doc.set(TABLE_FIELD, rows)
+
+	# 3) refresh the per-row "Tax Articles" display label
+	by_row = {}
+	for r in rows:
+		by_row.setdefault(r.parent_row, []).append(r.tax_article)
+
+	for item in doc.get("items", []):
+		articles = by_row.get(item.get(row_key_field), [])
+		if hasattr(item, DISPLAY_FIELD):
+			item.set(DISPLAY_FIELD, display_label(len(articles)))
+
+
+def display_label(n: int) -> str:
+	"""Short summary shown in the grid cell (avoids the Data field length limit)."""
+	if n:
+		return frappe._("{0} selected").format(n)
+	return frappe._("Click to select")
diff --git a/jey_erp/custom/sales_invoice_tax_articles.py b/jey_erp/custom/sales_invoice_tax_articles.py
index d7c4e55..1224be8 100644
--- a/jey_erp/custom/sales_invoice_tax_articles.py
+++ b/jey_erp/custom/sales_invoice_tax_articles.py
@@ -1,61 +1,15 @@
-# Sales Invoice multi tax-article — server-side foundation.
+# Sales Invoice binding for the shared multi tax-article foundation.
+# All logic lives in item_tax_articles.py — this file is just the validate entry point.
 #
-# Source of truth for the (possibly multiple) tax articles of an invoice line is
-# the parent table `custom_item_tax_articles` (child DocType "Sales Invoice Tax
-# Article"), whose rows are linked to an item row by `custom_si_row_key`.
-#
-# This validate hook:
-#   1. guarantees every item row has a stable `custom_si_row_key` (so SQL joins
-#      from `Sales Invoice Item` to `Sales Invoice Tax Article` are reliable),
-#   2. drops ONLY orphaned article rows (whose parent_row matches no item row) —
-#      the user's selection is otherwise kept regardless of tax template,
-#   3. refreshes the `custom_tax_articles_display` text (the grid cell summary).
-#
-# It deliberately does NOT write the legacy single `tax_article` field: after
-# Phase 2 the consumers (VAT Allocation, tax reports) JOIN the child table, so the
-# single field is unused on Sales Invoice — and writing it fought vat_calculator.js
-# (which clears it on refresh for non-0% lines), leaving the form perpetually dirty.
+# Child DocType: "Sales Invoice Tax Article", parent table `custom_item_tax_articles`,
+# rows linked to an item row by `custom_si_row_key`.
 
-import frappe
+from jey_erp.custom.item_tax_articles import sync
+
+ROW_KEY = "custom_si_row_key"
 
 
 def sync_item_tax_articles(doc, method=None):
-    if doc.doctype != "Sales Invoice":
-        return
-
-    # 1) ensure each item row has a unique, stable row key (links it to its articles)
-    seen = set()
-    for item in doc.get("items", []):
-        key = item.get("custom_si_row_key")
-        if not key or key in seen:
-            key = "r" + frappe.generate_hash(length=10)
-            item.custom_si_row_key = key
-        seen.add(key)
-
-    # 2) keep every article row that points at a real item row; drop only orphans.
-    #    NOTE: we intentionally do NOT drop by item_tax_template — the user's
-    #    selection must survive saving even if the template is empty/non-0%.
-    item_keys = {item.custom_si_row_key for item in doc.get("items", [])}
-    rows = [
-        r
-        for r in (doc.get("custom_item_tax_articles") or [])
-        if r.get("parent_row") in item_keys and r.get("tax_article")
-    ]
-    doc.custom_item_tax_articles = rows
-
-    # 3) refresh the per-row "Tax Articles" display label
-    by_row = {}
-    for r in rows:
-        by_row.setdefault(r.parent_row, []).append(r.tax_article)
-
-    for item in doc.get("items", []):
-        articles = by_row.get(item.custom_si_row_key, [])
-        if hasattr(item, "custom_tax_articles_display"):
-            item.custom_tax_articles_display = _display_label(len(articles))
-
-
-def _display_label(n: int) -> str:
-    """Short summary shown in the grid cell (avoids the Data field length limit)."""
-    if n:
-        return frappe._("{0} selected").format(n)
-    return frappe._("Click to select")
+	if doc.doctype != "Sales Invoice":
+		return
+	sync(doc, ROW_KEY)
diff --git a/jey_erp/custom/sales_order_tax_articles.py b/jey_erp/custom/sales_order_tax_articles.py
new file mode 100644
index 0000000..dfaa095
--- /dev/null
+++ b/jey_erp/custom/sales_order_tax_articles.py
@@ -0,0 +1,77 @@
+# Sales Order binding for the shared multi tax-article foundation, plus the carry-over
+# into the Sales Invoice when an order is converted.
+#
+# Child DocType: "Sales Order Tax Article", parent table `custom_item_tax_articles`,
+# rows linked to an item row by `custom_so_row_key`.
+
+import frappe
+
+from jey_erp.custom.item_tax_articles import display_label, sync
+
+ROW_KEY = "custom_so_row_key"
+SI_ROW_KEY = "custom_si_row_key"
+TABLE_FIELD = "custom_item_tax_articles"
+
+
+def sync_item_tax_articles(doc, method=None):
+	if doc.doctype != "Sales Order":
+		return
+	sync(doc, ROW_KEY)
+
+
+@frappe.whitelist()
+def make_sales_invoice(source_name, target_doc=None, ignore_permissions=False):
+	"""ERPNext's Sales Order -> Sales Invoice mapper, plus the tax articles.
+
+	get_mapped_doc only walks the standard field map, so a custom parent-level table
+	(and the row keys that tie it to the item rows) is not carried over — without this
+	the accountant would pick articles on the order and find the invoice empty.
+
+	Row keys are regenerated rather than copied: `custom_si_row_key` is no_copy, and the
+	two documents key their rows independently. The order's rows are matched to the
+	invoice's via `so_detail`, which ERPNext stamps on each mapped invoice line.
+
+	Only fires on the whitelisted (UI "Create > Sales Invoice") path. A Sales Invoice
+	built by other means still gets valid — just empty — article tables, and the
+	accountant can fill them in as usual.
+	"""
+	from erpnext.selling.doctype.sales_order.sales_order import (
+		make_sales_invoice as _make_sales_invoice,
+	)
+
+	target = _make_sales_invoice(source_name, target_doc, ignore_permissions)
+	_carry_over_tax_articles(source_name, target)
+	return target
+
+
+def _carry_over_tax_articles(source_name, target):
+	so = frappe.get_doc("Sales Order", source_name)
+
+	# so item row name -> that row's article key
+	key_by_item = {
+		item.name: item.get(ROW_KEY) for item in so.get("items", []) if item.get(ROW_KEY)
+	}
+	if not key_by_item:
+		return
+
+	# article key -> [tax article, ...]
+	articles_by_key = {}
+	for row in so.get(TABLE_FIELD) or []:
+		if row.parent_row and row.tax_article:
+			articles_by_key.setdefault(row.parent_row, []).append(row.tax_article)
+	if not articles_by_key:
+		return
+
+	for item in target.get("items", []):
+		so_key = key_by_item.get(item.get("so_detail"))
+		articles = articles_by_key.get(so_key) if so_key else None
+		if not articles:
+			continue
+
+		si_key = item.get(SI_ROW_KEY) or ("r" + frappe.generate_hash(length=10))
+		item.set(SI_ROW_KEY, si_key)
+
+		for article in articles:
+			target.append(TABLE_FIELD, {"parent_row": si_key, "tax_article": article})
+
+		item.set("custom_tax_articles_display", display_label(len(articles)))
diff --git a/jey_erp/custom_fields.py b/jey_erp/custom_fields.py
index eb00ac3..0d2ae50 100644
--- a/jey_erp/custom_fields.py
+++ b/jey_erp/custom_fields.py
@@ -741,6 +741,23 @@ def create_custom_fields():
                 fieldtype='Check',
                 insert_after='taxes_doc',
                 default=0
+            ),
+            # Per-item multiple tax articles: parent-level backing table, linked to each
+            # item row by custom_so_row_key (Frappe has no nested child tables, so this
+            # lives on the parent, not the row). Mirrors Sales Invoice.
+            dict(
+                fieldname='custom_item_tax_articles_section',
+                label='Item Tax Articles',
+                fieldtype='Section Break',
+                insert_after='items',
+                collapsible=1
+            ),
+            dict(
+                fieldname='custom_item_tax_articles',
+                label='Item Tax Articles',
+                fieldtype='Table',
+                options='Sales Order Tax Article',
+                insert_after='custom_item_tax_articles_section'
             )
         ],
         "Sales Order Item": [
@@ -797,13 +814,36 @@ def create_custom_fields():
             ),
             dict(
                 fieldname='tax_article',
-                label='Tax Article',
+                label='Tax Article (primary)',
                 fieldtype='Link',
                 options='Tax Article',
                 insert_after='vat_free_amount',
+                in_list_view=0,
+                hidden=1,
+                read_only=1,
+                no_copy=1,
+                description='Deprecated single-value field, no longer populated. Tax articles are stored per item row in the "Tax Articles" multi-select cell (custom_item_tax_articles). Kept for historic data only.'
+            ),
+            # --- multi tax-article per item row (click the cell to edit) ---
+            dict(
+                fieldname='custom_so_row_key',
+                label='Row Key',
+                fieldtype='Data',
+                insert_after='tax_article',
+                read_only=1,
+                hidden=1,
+                no_copy=1
+            ),
+            dict(
+                fieldname='custom_tax_articles_display',
+                label='Tax Articles',
+                fieldtype='Data',
+                insert_after='custom_so_row_key',
+                read_only=1,
                 in_list_view=1,
+                hidden=0,
                 columns=2,
-                description='Tax Article field for VAT purposes'
+                description='Click to select tax articles'
             )
         ],
         "Sales Invoice": [
diff --git a/jey_erp/hooks.py b/jey_erp/hooks.py
index 3f4ce67..b808f6d 100644
--- a/jey_erp/hooks.py
+++ b/jey_erp/hooks.py
@@ -28,15 +28,20 @@ doctype_js = {
     # overflowing it returns 502 (see jey_layout/hooks.py).
     # ORDER MATTERS: vat_calculator.js defines jey_erp.vat_calculator and the
     # *_vat.js scripts call .init() at load time, so it must be listed first.
+    # Same for item_tax_articles.js, which defines jey_erp.item_tax_articles and is
+    # .init()-ed by the *_tax_articles.js config shims below it.
     "Sales Invoice": [
         "public/js/vat_calculator.js",
         "public/js/sales_invoice_vat.js",
+        "public/js/item_tax_articles.js",
         "public/js/sales_invoice_tax_articles.js",
         "public/js/sales_invoice_certificates.js",
     ],
     "Sales Order": [
         "public/js/vat_calculator.js",
         "public/js/sales_order_vat.js",
+        "public/js/item_tax_articles.js",
+        "public/js/sales_order_tax_articles.js",
     ],
     "Asset": "public/js/asset.js",
     "Purchase Invoice": "public/js/purchase_invoice.js",
@@ -60,6 +65,13 @@ extend_doctype_class = {
     "Payment Request": "jey_erp.custom.payment_request.PaymentRequestMixin",
 }
 
+# get_mapped_doc only walks the standard field map, so the per-item tax articles picked
+# on a Sales Order would be dropped on conversion. Wrap the mapper to carry them over.
+override_whitelisted_methods = {
+    "erpnext.selling.doctype.sales_order.sales_order.make_sales_invoice":
+        "jey_erp.custom.sales_order_tax_articles.make_sales_invoice",
+}
+
 override_doctype_class = {
     "Bulk Salary Structure Assignment": "jey_erp.custom.bulk_salary_structure_assignment.CustomBulkSalaryStructureAssignment",
     "Payroll Entry": "jey_erp.custom.payroll_entry.CustomPayrollEntry",
@@ -81,7 +93,8 @@ doc_events = {
     },
     "Sales Order": {
         "validate": [
-            "jey_erp.custom.sales_order_vat.set_vat_fields_permissions"
+            "jey_erp.custom.sales_order_vat.set_vat_fields_permissions",
+            "jey_erp.custom.sales_order_tax_articles.sync_item_tax_articles",
         ],
         "on_update": [
             "jey_erp.custom.sales_order_vat.set_vat_fields_permissions"
diff --git a/jey_erp/jey_erp/doctype/sales_invoice_tax_article/sales_invoice_tax_article.json b/jey_erp/jey_erp/doctype/sales_invoice_tax_article/sales_invoice_tax_article.json
index 13a89bb..6888fe0 100644
--- a/jey_erp/jey_erp/doctype/sales_invoice_tax_article/sales_invoice_tax_article.json
+++ b/jey_erp/jey_erp/doctype/sales_invoice_tax_article/sales_invoice_tax_article.json
@@ -21,7 +21,7 @@
    "fieldtype": "Link",
    "in_list_view": 1,
    "label": "Tax Article",
-   "link_filters": "[[\"Tax Article\",\"parent_tax_article\",\"in\",[\"ƏDV-yə 0% dərəcə ilə tutulan əməliyyatlar\",\"ƏDV-dən azad olunan əməliyyatlar\"]]]",
+   "link_filters": "[[\"Tax Article\",\"parent_tax_article\",\"in\",[\"ƏDV-yə 0% dərəcə ilə tutulan əməliyyatlar\",\"ƏDV-dən azad olunan əməliyyatlar\"]],[\"Tax Article\",\"name\",\"not like\",\"302.6%\"]]",
    "options": "Tax Article",
    "reqd": 1
   }
diff --git a/jey_erp/jey_erp/doctype/sales_order_tax_article/__init__.py b/jey_erp/jey_erp/doctype/sales_order_tax_article/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/jey_erp/jey_erp/doctype/sales_order_tax_article/sales_order_tax_article.json b/jey_erp/jey_erp/doctype/sales_order_tax_article/sales_order_tax_article.json
new file mode 100644
index 0000000..d93e37e
--- /dev/null
+++ b/jey_erp/jey_erp/doctype/sales_order_tax_article/sales_order_tax_article.json
@@ -0,0 +1,41 @@
+{
+ "actions": [],
+ "creation": "2026-07-14 00:00:00.000000",
+ "doctype": "DocType",
+ "editable_grid": 1,
+ "engine": "InnoDB",
+ "field_order": [
+  "parent_row",
+  "tax_article"
+ ],
+ "fields": [
+  {
+   "fieldname": "parent_row",
+   "fieldtype": "Data",
+   "in_list_view": 1,
+   "label": "Item Row Key",
+   "read_only": 1
+  },
+  {
+   "fieldname": "tax_article",
+   "fieldtype": "Link",
+   "in_list_view": 1,
+   "label": "Tax Article",
+   "link_filters": "[[\"Tax Article\",\"parent_tax_article\",\"in\",[\"ƏDV-yə 0% dərəcə ilə tutulan əməliyyatlar\",\"ƏDV-dən azad olunan əməliyyatlar\"]],[\"Tax Article\",\"name\",\"not like\",\"302.6%\"]]",
+   "options": "Tax Article",
+   "reqd": 1
+  }
+ ],
+ "index_web_pages_for_search": 1,
+ "istable": 1,
+ "links": [],
+ "modified": "2026-07-14 00:00:00.000000",
+ "modified_by": "Administrator",
+ "module": "Jey Erp",
+ "name": "Sales Order Tax Article",
+ "owner": "Administrator",
+ "permissions": [],
+ "sort_field": "modified",
+ "sort_order": "DESC",
+ "states": []
+}
diff --git a/jey_erp/jey_erp/doctype/sales_order_tax_article/sales_order_tax_article.py b/jey_erp/jey_erp/doctype/sales_order_tax_article/sales_order_tax_article.py
new file mode 100644
index 0000000..191e946
--- /dev/null
+++ b/jey_erp/jey_erp/doctype/sales_order_tax_article/sales_order_tax_article.py
@@ -0,0 +1,8 @@
+# Copyright (c) 2026, Ali and contributors
+# For license information, please see license.txt
+
+from frappe.model.document import Document
+
+
+class SalesOrderTaxArticle(Document):
+	pass
diff --git a/jey_erp/patches.txt b/jey_erp/patches.txt
index 8e84eee..f5b9d87 100644
--- a/jey_erp/patches.txt
+++ b/jey_erp/patches.txt
@@ -16,4 +16,5 @@ jey_erp.patches.drop_orphan_bank_doctypes
 jey_erp.patches.backfill_si_tax_article_row_keys
 jey_erp.patches.backfill_sales_invoice_tax_articles_history
 jey_erp.patches.add_tax_articles_to_si_grid_views
-jey_erp.patches.add_certificates_to_si_grid_views
\ No newline at end of file
+jey_erp.patches.add_certificates_to_si_grid_views
+jey_erp.patches.add_tax_articles_to_so_grid_views
diff --git a/jey_erp/patches/add_tax_articles_to_so_grid_views.py b/jey_erp/patches/add_tax_articles_to_so_grid_views.py
new file mode 100644
index 0000000..2cc89de
--- /dev/null
+++ b/jey_erp/patches/add_tax_articles_to_so_grid_views.py
@@ -0,0 +1,56 @@
+import json
+
+import frappe
+
+
+def execute():
+	"""Inject the new "Tax Articles" column into saved Sales Order Item grid layouts.
+
+	Same story as add_tax_articles_to_si_grid_views, one doctype over. Per-user grid
+	column layouts live in `__UserSettings` (GridView). A layout saved before the multi
+	tax-article feature lists the legacy `tax_article` column but not the new
+	`custom_tax_articles_display`. Frappe renders that saved list verbatim and ignores
+	the new in_list_view field, so the "Tax Articles" cell never appears for those users
+	until they add it manually via the grid gear.
+
+	Add `custom_tax_articles_display` to every saved layout that doesn't already have it,
+	positioned near the tax fields. The legacy `tax_article` column is left in place if a
+	layout lists it — the field is hidden now, so Frappe simply won't render it.
+	Idempotent.
+	"""
+	rows = frappe.db.sql(
+		"select user, data from `__UserSettings` where doctype = 'Sales Order'",
+		as_dict=True,
+	)
+	for r in rows:
+		try:
+			data = json.loads(r.data or "{}")
+		except (ValueError, TypeError):
+			continue
+
+		grid_view = data.get("GridView") or {}
+		cols = grid_view.get("Sales Order Item")
+		if not cols:
+			continue
+
+		names = [c.get("fieldname") for c in cols]
+		if "custom_tax_articles_display" in names:
+			continue
+
+		new_col = {"fieldname": "custom_tax_articles_display", "columns": 2}
+		if "item_tax_template" in names:
+			cols.insert(names.index("item_tax_template") + 1, new_col)
+		elif "tax_article" in names:
+			cols.insert(names.index("tax_article") + 1, new_col)
+		else:
+			cols.append(new_col)
+
+		grid_view["Sales Order Item"] = cols
+		data["GridView"] = grid_view
+		frappe.db.sql(
+			"update `__UserSettings` set data = %s where user = %s and doctype = 'Sales Order'",
+			(json.dumps(data), r.user),
+		)
+
+	frappe.db.commit()
+	frappe.cache().delete_value("_user_settings")
diff --git a/jey_erp/public/js/item_tax_articles.js b/jey_erp/public/js/item_tax_articles.js
new file mode 100644
index 0000000..6a9fd40
--- /dev/null
+++ b/jey_erp/public/js/item_tax_articles.js
@@ -0,0 +1,282 @@
+// Multiple Tax Articles per item row — shared by Sales Invoice and Sales Order.
+//
+// Click the read-only "Tax Articles" cell -> a dialog opens with a Table MultiSelect
+// field (a Link control under the hood => native search + native Advanced Search)
+// pre-filled with the row's articles as pills. Source of truth = a parent-level table
+// (Frappe has no nested child tables), whose rows point back at an item row by a
+// generated row key.
+//
+// The article list is filtered to the parent group matching the line's tax template
+// (ƏDV 0% -> 0% group, ƏDV-dən azadolma -> exempt group, ƏDV 18% -> taxable-turnover
+// group); the dialog only opens for those templates. Note: ƏDV daxil 18% (VAT
+// included) is intentionally excluded — it gets no tax articles.
+//
+// Callers pass a config (see sales_invoice_tax_articles.js / sales_order_tax_articles.js):
+//   doctype          "Sales Invoice"              parent form
+//   item_doctype     "Sales Invoice Item"         item grid rows
+//   child_doctype    "Sales Invoice Tax Article"  the parent-level backing table's DocType
+//   table_field      "custom_item_tax_articles"   Table field on the parent
+//   row_key          "custom_si_row_key"          Data field on the item row
+//   cert_table_field "custom_item_certificates"   optional; lines with a certificate are
+//                                                 locked (the certificate drives the 0%
+//                                                 treatment). Pass null where absent.
+
+if (!window.jey_erp) {
+	window.jey_erp = {};
+}
+
+jey_erp.item_tax_articles = (function () {
+	const DIALOG_CLASS = "tax-articles-dialog";
+	const DISPLAY_FIELD = "custom_tax_articles_display";
+
+	const GROUP_ZERO = "ƏDV-yə 0% dərəcə ilə tutulan əməliyyatlar";
+	const GROUP_EXEMPT = "ƏDV-dən azad olunan əməliyyatlar";
+	const GROUP_TAXABLE_18 = "ƏDV tutulan dövriyyə barədə məlumat";
+
+	// 302.6 (production-sharing / pipeline / oil-and-gas agreements) and its 302.6.1
+	// advance-payment sub-line are not something a sales line gets tagged with, so they
+	// never appear in this picker. They stay selectable everywhere else — Payment Entry,
+	// Asset, the Tax Article tree itself.
+	//
+	// Matched on the ФНО code rather than the article name: names get re-worded to track
+	// the e-taxes cabinet, and a stale name in an exclusion list fails open — the article
+	// quietly reappears in the picker. The trailing % catches 302.6 and 302.6.1 while
+	// leaving 302.7 / 302.11 / 302.12 alone. The same pattern is mirrored in the child
+	// DocType's link_filters, which is what guards the parent-level table when it is
+	// edited directly instead of through this dialog.
+	const EXCLUDED_CODE_PATTERN = "302.6%";
+
+	function tax_article_group_for(template) {
+		const t = (template || "").trim();
+		if (t.indexOf("ƏDV 0%") === 0) return GROUP_ZERO;
+		if (t.indexOf("ƏDV-dən azadolma") === 0) return GROUP_EXEMPT;
+		// "ƏDV 18%" (VAT on top) only — "ƏDV daxil 18%" does NOT match this prefix,
+		// so the VAT-included variant deliberately gets no tax articles.
+		if (t.indexOf("ƏDV 18%") === 0) return GROUP_TAXABLE_18;
+		return null;
+	}
+
+	function inject_styles() {
+		if (document.getElementById("taxmulti-style")) return;
+		const style = document.createElement("style");
+		style.id = "taxmulti-style";
+		const F = DISPLAY_FIELD;
+		const D = "." + DIALOG_CLASS;
+		style.textContent = [
+			// grid cell: clickable, click passes through the read-only input
+			'.grid-row [data-fieldname="' + F + '"]{cursor:pointer;}',
+			'.grid-row [data-fieldname="' + F + '"] input,',
+			'.grid-row [data-fieldname="' + F + '"] textarea,',
+			'.grid-row [data-fieldname="' + F + '"] .like-disabled-input{pointer-events:none;}',
+
+			// keep the dropdown (incl. native "Advanced Search") reachable, not clipped
+			D + " .modal-body," + D + " .frappe-control," + D + " .form-group," +
+				D + " .control-input-wrapper{overflow:visible!important;}",
+			D + " .awesomplete > ul{max-height:260px;overflow-y:auto;z-index:1080;}",
+
+			// ONE seamless surface: keep only the single .modal-content gradient
+			D + " .modal-header," + D + " .modal-body," + D + " .modal-footer," +
+				D + " .form-layout," + D + " .form-page," + D + " .form-section," +
+				D + " .section-body," + D + " .form-column," + D + " .table-multiselect{" +
+				"background:transparent!important;background-image:none!important;" +
+				"box-shadow:none!important;border:none!important;}",
+
+			// thin dividers under the title and above the footer
+			D + " .modal-header{border-bottom:1px solid rgba(0,0,0,.15)!important;}",
+			D + " .modal-footer{border-top:1px solid rgba(0,0,0,.12)!important;}",
+
+			// trim the empty space above the field
+			D + " .modal-body{padding-top:14px!important;}",
+
+			// the search input as its own bordered field, just below the pills
+			D + " .table-multiselect .awesomplete{display:block;width:100%;margin-top:8px;}",
+			D + " .table-multiselect .awesomplete input{display:block;width:100%;" +
+				"border:1px solid var(--border-color,#999)!important;" +
+				"border-radius:var(--border-radius,6px)!important;padding:4px 8px!important;min-height:28px;}",
+		].join("");
+		document.head.appendChild(style);
+	}
+
+	function ensure_setup(frm, cfg) {
+		if (frm.__tax_articles_bound) return;
+		frm.__tax_articles_bound = true;
+
+		// Namespaced per doctype: Sales Invoice and Sales Order both bind this, and a
+		// shared namespace would make the second .off() tear the first one's handler off
+		// the document — silently breaking the cell click on whichever form was opened
+		// first. The doctype guard below keeps the other form's handler inert.
+		const ns = "mousedown.taxmulti_" + cfg.doctype.replace(/\s+/g, "_");
+
+		$(document)
+			.off(ns)
+			.on(ns, '[data-fieldname="' + DISPLAY_FIELD + '"]', function (ev) {
+				const grid_row = $(this).closest(".grid-row").data("grid_row");
+				const doc = grid_row && grid_row.doc;
+				if (!doc || doc.doctype !== cfg.item_doctype) return;
+				if (!frm.fields_dict.items || !frm.fields_dict.items.grid) return;
+				ev.stopPropagation();
+				open_dialog(frm, doc.name, cfg);
+			});
+	}
+
+	function open_dialog(frm, cdn, cfg) {
+		const row = locals[cfg.item_doctype][cdn];
+		if (!row) return;
+
+		// A line with a presented certificate is locked — the certificate, not the
+		// article, drives its 0% treatment. Sales Order has no certificates, so cfg
+		// leaves cert_table_field null and this check is skipped.
+		if (cfg.cert_table_field) {
+			const cert_key = row[cfg.row_key];
+			const has_cert =
+				cert_key &&
+				(frm.doc[cfg.cert_table_field] || []).some(
+					(r) => r.parent_row === cert_key && r.certificate
+				);
+			if (has_cert) {
+				frappe.show_alert({
+					message: __(
+						"Tax articles are read-only while a certificate is selected for this line. Remove the certificate to edit them."
+					),
+					indicator: "orange",
+				});
+				return;
+			}
+		}
+
+		const group = tax_article_group_for(row.item_tax_template);
+		if (!group) {
+			frappe.show_alert({
+				message: __(
+					"Tax articles apply only to ƏDV 0% / ƏDV-dən azadolma / ƏDV 18% lines. Set the item's Tax Template first."
+				),
+				indicator: "orange",
+			});
+			return;
+		}
+
+		if (!row[cfg.row_key]) {
+			row[cfg.row_key] = "r" + Math.random().toString(36).slice(2, 12);
+		}
+		const key = row[cfg.row_key];
+
+		// Table MultiSelect value = array of child-row objects keyed by the link field.
+		const current = (frm.doc[cfg.table_field] || [])
+			.filter((r) => r.parent_row === key && r.tax_article)
+			.map((r) => ({ tax_article: r.tax_article }));
+
+		const d = new frappe.ui.Dialog({
+			title: __("Tax Articles") + " — " + (row.item_code || "#" + row.idx),
+			fields: [
+				{
+					fieldname: "articles",
+					fieldtype: "Table MultiSelect",
+					label: __("Select tax articles"),
+					options: cfg.child_doctype,
+					get_query() {
+						return {
+							filters: {
+								parent_tax_article: group,
+								name: ["not like", EXCLUDED_CODE_PATTERN],
+							},
+						};
+					},
+				},
+			],
+			primary_action_label: __("Save"),
+			primary_action(values) {
+				const selected = Array.from(
+					new Set((values.articles || []).map((r) => r.tax_article).filter(Boolean))
+				);
+				frm.doc[cfg.table_field] = (frm.doc[cfg.table_field] || []).filter(
+					(r) => r.parent_row !== key
+				);
+				selected.forEach((a) => {
+					const c = frm.add_child(cfg.table_field);
+					c.parent_row = key;
+					c.tax_article = a;
+				});
+				const display = selected.length
+					? __("{0} selected", [selected.length])
+					: __("Click to select");
+				frappe.model.set_value(row.doctype, row.name, DISPLAY_FIELD, display);
+				frm.refresh_field(cfg.table_field);
+				frm.refresh_field("items");
+				d.hide();
+			},
+		});
+
+		d.$wrapper.addClass(DIALOG_CLASS);
+		d.add_custom_action(__("Clear all"), () => d.set_value("articles", []));
+
+		// Robust pill removal inside a Dialog. Table MultiSelect's own `.btn-remove`
+		// handler does not update the field value in a dialog (it relies on a form's child
+		// docs), which causes the "needs a second click / removes the wrong pills"
+		// behaviour. We intercept the click in the CAPTURE phase, stop the control's broken
+		// handler, and do the removal ourselves: value = current minus the clicked article.
+		const fld = d.fields_dict.articles;
+		fld.$wrapper[0].addEventListener(
+			"click",
+			function (e) {
+				const btn = e.target.closest(".btn-remove");
+				if (!btn) return;
+				e.stopPropagation();
+				const pill = btn.closest(".tb-selected-value");
+				const removed = pill ? decodeURIComponent(pill.getAttribute("data-value") || "") : "";
+				const remaining = (fld.get_value() || [])
+					.map((r) => (typeof r === "string" ? r : r && r.tax_article))
+					.filter((n) => n && n !== removed)
+					.map((n) => ({ tax_article: n }));
+				fld.set_value(remaining);
+			},
+			true
+		);
+
+		d.set_value("articles", current);
+		d.show();
+	}
+
+	// Wire a parent doctype up. Called once per form script at load time.
+	function init(cfg) {
+		inject_styles();
+
+		frappe.ui.form.on(cfg.doctype, {
+			onload: (frm) => ensure_setup(frm, cfg),
+			refresh: (frm) => ensure_setup(frm, cfg),
+		});
+
+		frappe.ui.form.on(cfg.item_doctype, {
+			// When the tax template changes, the row's already-selected articles belong to
+			// the previous template's group and are no longer valid -> clear them and warn.
+			item_tax_template(frm, cdt, cdn) {
+				const row = locals[cdt][cdn];
+				if (!row || !row[cfg.row_key]) return;
+
+				const key = row[cfg.row_key];
+				const had = (frm.doc[cfg.table_field] || []).some((r) => r.parent_row === key);
+				if (!had) return;
+
+				frm.doc[cfg.table_field] = (frm.doc[cfg.table_field] || []).filter(
+					(r) => r.parent_row !== key
+				);
+				frm.refresh_field(cfg.table_field);
+
+				const allowed = !!tax_article_group_for(row.item_tax_template);
+				frappe.model.set_value(cdt, cdn, DISPLAY_FIELD, allowed ? __("Click to select") : "");
+
+				frappe.show_alert(
+					{
+						message: __(
+							"Tax articles for {0} were cleared because the tax template changed.",
+							[row.item_code || "#" + row.idx]
+						),
+						indicator: "orange",
+					},
+					7
+				);
+			},
+		});
+	}
+
+	return { init, tax_article_group_for, EXCLUDED_CODE_PATTERN };
+})();
diff --git a/jey_erp/public/js/sales_invoice_tax_articles.js b/jey_erp/public/js/sales_invoice_tax_articles.js
index d549dc2..232a7ce 100644
--- a/jey_erp/public/js/sales_invoice_tax_articles.js
+++ b/jey_erp/public/js/sales_invoice_tax_articles.js
@@ -1,233 +1,17 @@
-// Multiple Tax Articles per Sales Invoice Item row.
-// Click the read-only "Tax Articles" cell -> a dialog opens with a Table MultiSelect
-// field (a Link control under the hood => native search + native Advanced Search)
-// pre-filled with the row's articles as pills. Source of truth = parent table
-// `custom_item_tax_articles`, linked to each item row by `custom_si_row_key`.
+// Sales Invoice binding for the shared multi tax-article picker.
+// All behaviour lives in item_tax_articles.js — this file is just the config.
 //
-// The article list is filtered to the parent group matching the line's tax template
-// (ƏDV 0% -> 0% group, ƏDV-dən azadolma -> exempt group, ƏDV 18% -> taxable-turnover
-// group); the dialog only opens for those templates. Note: ƏDV daxil 18% (VAT
-// included) is intentionally excluded — it gets no tax articles.
+// This dialog is the ONLY tax-article picker on Sales Invoice: the single
+// `Sales Invoice Item.tax_article` link field is hidden/read-only and deprecated
+// (kept for historic rows).
+//
+// ORDER MATTERS: item_tax_articles.js must load first (see doctype_js in hooks.py).
 
-const DIALOG_CLASS = "tax-articles-dialog";
-const CHILD_DOCTYPE = "Sales Invoice Tax Article";
-const DISPLAY_FIELD = "custom_tax_articles_display";
-
-const GROUP_ZERO = "ƏDV-yə 0% dərəcə ilə tutulan əməliyyatlar";
-const GROUP_EXEMPT = "ƏDV-dən azad olunan əməliyyatlar";
-const GROUP_TAXABLE_18 = "ƏDV tutulan dövriyyə barədə məlumat";
-
-function tax_article_group_for(template) {
-	const t = (template || "").trim();
-	if (t.indexOf("ƏDV 0%") === 0) return GROUP_ZERO;
-	if (t.indexOf("ƏDV-dən azadolma") === 0) return GROUP_EXEMPT;
-	// "ƏDV 18%" (VAT on top) only — "ƏDV daxil 18%" does NOT match this prefix,
-	// so the VAT-included variant deliberately gets no tax articles.
-	if (t.indexOf("ƏDV 18%") === 0) return GROUP_TAXABLE_18;
-	return null;
-}
-
-if (!document.getElementById("taxmulti-style")) {
-	const style = document.createElement("style");
-	style.id = "taxmulti-style";
-	const F = DISPLAY_FIELD;
-	const D = "." + DIALOG_CLASS;
-	style.textContent = [
-		// grid cell: clickable, click passes through the read-only input
-		'.grid-row [data-fieldname="' + F + '"]{cursor:pointer;}',
-		'.grid-row [data-fieldname="' + F + '"] input,',
-		'.grid-row [data-fieldname="' + F + '"] textarea,',
-		'.grid-row [data-fieldname="' + F + '"] .like-disabled-input{pointer-events:none;}',
-
-		// keep the dropdown (incl. native "Advanced Search") reachable, not clipped
-		D + " .modal-body," + D + " .frappe-control," + D + " .form-group," +
-			D + " .control-input-wrapper{overflow:visible!important;}",
-		D + " .awesomplete > ul{max-height:260px;overflow-y:auto;z-index:1080;}",
-
-		// ONE seamless surface: keep only the single .modal-content gradient
-		D + " .modal-header," + D + " .modal-body," + D + " .modal-footer," +
-			D + " .form-layout," + D + " .form-page," + D + " .form-section," +
-			D + " .section-body," + D + " .form-column," + D + " .table-multiselect{" +
-			"background:transparent!important;background-image:none!important;" +
-			"box-shadow:none!important;border:none!important;}",
-
-		// thin dividers under the title and above the footer
-		D + " .modal-header{border-bottom:1px solid rgba(0,0,0,.15)!important;}",
-		D + " .modal-footer{border-top:1px solid rgba(0,0,0,.12)!important;}",
-
-		// trim the empty space above the field
-		D + " .modal-body{padding-top:14px!important;}",
-
-		// the search input as its own bordered field, just below the pills
-		D + " .table-multiselect .awesomplete{display:block;width:100%;margin-top:8px;}",
-		D + " .table-multiselect .awesomplete input{display:block;width:100%;" +
-			"border:1px solid var(--border-color,#999)!important;" +
-			"border-radius:var(--border-radius,6px)!important;padding:4px 8px!important;min-height:28px;}",
-	].join("");
-	document.head.appendChild(style);
-}
-
-frappe.ui.form.on("Sales Invoice", {
-	onload(frm) {
-		ensure_setup(frm);
-	},
-	refresh(frm) {
-		ensure_setup(frm);
-	},
+jey_erp.item_tax_articles.init({
+	doctype: "Sales Invoice",
+	item_doctype: "Sales Invoice Item",
+	child_doctype: "Sales Invoice Tax Article",
+	table_field: "custom_item_tax_articles",
+	row_key: "custom_si_row_key",
+	cert_table_field: "custom_item_certificates",
 });
-
-frappe.ui.form.on("Sales Invoice Item", {
-	// When the tax template changes, the row's already-selected articles belong to the
-	// previous template's group and are no longer valid -> clear them and warn.
-	item_tax_template(frm, cdt, cdn) {
-		const row = locals[cdt][cdn];
-		if (!row || !row.custom_si_row_key) return;
-
-		const key = row.custom_si_row_key;
-		const had = (frm.doc.custom_item_tax_articles || []).some((r) => r.parent_row === key);
-		if (!had) return;
-
-		frm.doc.custom_item_tax_articles = (frm.doc.custom_item_tax_articles || []).filter(
-			(r) => r.parent_row !== key
-		);
-		frm.refresh_field("custom_item_tax_articles");
-
-		const allowed = !!tax_article_group_for(row.item_tax_template);
-		frappe.model.set_value(cdt, cdn, DISPLAY_FIELD, allowed ? __("Click to select") : "");
-
-		frappe.show_alert(
-			{
-				message: __("Tax articles for {0} were cleared because the tax template changed.", [
-					row.item_code || "#" + row.idx,
-				]),
-				indicator: "orange",
-			},
-			7
-		);
-	},
-});
-
-function ensure_setup(frm) {
-	if (frm.__tax_articles_bound) return;
-	frm.__tax_articles_bound = true;
-
-	$(document)
-		.off("mousedown.taxmulti")
-		.on("mousedown.taxmulti", '[data-fieldname="' + DISPLAY_FIELD + '"]', function (ev) {
-			const grid_row = $(this).closest(".grid-row").data("grid_row");
-			const cdn = grid_row && grid_row.doc && grid_row.doc.name;
-			if (cdn && frm.fields_dict.items && frm.fields_dict.items.grid) {
-				ev.stopPropagation();
-				open_tax_article_dialog(frm, cdn);
-			}
-		});
-}
-
-function open_tax_article_dialog(frm, cdn) {
-	const row = locals["Sales Invoice Item"][cdn];
-	if (!row) return;
-
-	// Tax articles are locked (read-only) for a line that already has a presented
-	// certificate — the certificate determines the 0% treatment for that line.
-	const cert_key = row.custom_si_row_key;
-	const has_cert =
-		cert_key &&
-		(frm.doc.custom_item_certificates || []).some(
-			(r) => r.parent_row === cert_key && r.certificate
-		);
-	if (has_cert) {
-		frappe.show_alert({
-			message: __(
-				"Tax articles are read-only while a certificate is selected for this line. Remove the certificate to edit them."
-			),
-			indicator: "orange",
-		});
-		return;
-	}
-
-	const group = tax_article_group_for(row.item_tax_template);
-	if (!group) {
-		frappe.show_alert({
-			message: __(
-				"Tax articles apply only to ƏDV 0% / ƏDV-dən azadolma / ƏDV 18% lines. Set the item's Tax Template first."
-			),
-			indicator: "orange",
-		});
-		return;
-	}
-
-	if (!row.custom_si_row_key) {
-		row.custom_si_row_key = "r" + Math.random().toString(36).slice(2, 12);
-	}
-	const key = row.custom_si_row_key;
-
-	// Table MultiSelect value = array of child-row objects keyed by the link field.
-	const current = (frm.doc.custom_item_tax_articles || [])
-		.filter((r) => r.parent_row === key && r.tax_article)
-		.map((r) => ({ tax_article: r.tax_article }));
-
-	const d = new frappe.ui.Dialog({
-		title: __("Tax Articles") + " — " + (row.item_code || "#" + row.idx),
-		fields: [
-			{
-				fieldname: "articles",
-				fieldtype: "Table MultiSelect",
-				label: __("Select tax articles"),
-				options: CHILD_DOCTYPE,
-				get_query() {
-					return { filters: { parent_tax_article: group } };
-				},
-			},
-		],
-		primary_action_label: __("Save"),
-		primary_action(values) {
-			const selected = Array.from(
-				new Set((values.articles || []).map((r) => r.tax_article).filter(Boolean))
-			);
-			frm.doc.custom_item_tax_articles = (frm.doc.custom_item_tax_articles || []).filter(
-				(r) => r.parent_row !== key
-			);
-			selected.forEach((a) => {
-				const c = frm.add_child("custom_item_tax_articles");
-				c.parent_row = key;
-				c.tax_article = a;
-			});
-			const display = selected.length
-				? __("{0} selected", [selected.length])
-				: __("Click to select");
-			frappe.model.set_value(row.doctype, row.name, DISPLAY_FIELD, display);
-			frm.refresh_field("custom_item_tax_articles");
-			frm.refresh_field("items");
-			d.hide();
-		},
-	});
-
-	d.$wrapper.addClass(DIALOG_CLASS);
-	d.add_custom_action(__("Clear all"), () => d.set_value("articles", []));
-
-	// Robust pill removal inside a Dialog. Table MultiSelect's own `.btn-remove`
-	// handler does not update the field value in a dialog (it relies on a form's child
-	// docs), which causes the "needs a second click / removes the wrong pills"
-	// behaviour. We intercept the click in the CAPTURE phase, stop the control's broken
-	// handler, and do the removal ourselves: value = current minus the clicked article.
-	const fld = d.fields_dict.articles;
-	fld.$wrapper[0].addEventListener(
-		"click",
-		function (e) {
-			const btn = e.target.closest(".btn-remove");
-			if (!btn) return;
-			e.stopPropagation();
-			const pill = btn.closest(".tb-selected-value");
-			const removed = pill ? decodeURIComponent(pill.getAttribute("data-value") || "") : "";
-			const remaining = (fld.get_value() || [])
-				.map((r) => (typeof r === "string" ? r : r && r.tax_article))
-				.filter((n) => n && n !== removed)
-				.map((n) => ({ tax_article: n }));
-			fld.set_value(remaining);
-		},
-		true
-	);
-
-	d.set_value("articles", current);
-	d.show();
-}
diff --git a/jey_erp/public/js/sales_order_tax_articles.js b/jey_erp/public/js/sales_order_tax_articles.js
new file mode 100644
index 0000000..d0c1f0a
--- /dev/null
+++ b/jey_erp/public/js/sales_order_tax_articles.js
@@ -0,0 +1,19 @@
+// Sales Order binding for the shared multi tax-article picker.
+// All behaviour lives in item_tax_articles.js — this file is just the config.
+//
+// Mirrors Sales Invoice one-for-one, minus certificates (Sales Order has none), so
+// cert_table_field is null and the certificate lock is skipped.
+//
+// The articles selected here ride along into the Sales Invoice when the order is
+// converted — see jey_erp.custom.sales_order_tax_articles.make_sales_invoice.
+//
+// ORDER MATTERS: item_tax_articles.js must load first (see doctype_js in hooks.py).
+
+jey_erp.item_tax_articles.init({
+	doctype: "Sales Order",
+	item_doctype: "Sales Order Item",
+	child_doctype: "Sales Order Tax Article",
+	table_field: "custom_item_tax_articles",
+	row_key: "custom_so_row_key",
+	cert_table_field: null,
+});
diff --git a/jey_erp/public/js/vat_calculator.js b/jey_erp/public/js/vat_calculator.js
index 0e2b7aa..53a4327 100644
--- a/jey_erp/public/js/vat_calculator.js
+++ b/jey_erp/public/js/vat_calculator.js
@@ -119,10 +119,13 @@ jey_erp.vat_calculator = {
     
     // 3. ОБНОВЛЕННАЯ функция с поддержкой индивидуальных фильтров для tax_article
     update_tax_article_readonly: function(frm, cdt, cdn) {
-        // On Sales Invoice the single `tax_article` field is vestigial (hidden;
-        // replaced by the multi-select child table). Touching/clearing it here
-        // marks the form dirty on every refresh — skip it entirely for Sales Invoice.
-        if (frm && frm.doctype === 'Sales Invoice') return;
+        // The single `tax_article` field is vestigial on both Sales Invoice and Sales
+        // Order (hidden; replaced by the multi-select child table driven by
+        // item_tax_articles.js). Touching/clearing it here marks the form dirty on every
+        // refresh, so skip it entirely. Nothing else calls this — the helpers below
+        // (is_tax_article_allowed / get_tax_article_filter / validate_tax_article_against_filter)
+        // are kept only for any doctype that still uses the plain link field.
+        if (frm && (frm.doctype === 'Sales Invoice' || frm.doctype === 'Sales Order')) return;
 
         const item = locals[cdt][cdn];
         if (!item?.item_code) return;