Anglo-Saxon Accounting in Odoo v19 — Full Investigation

What Is Anglo-Saxon Accounting?

A method that controls when COGS is recognised:

Method	COGS fires at	Used in
Continental	Vendor bill validation	France, Germany, most of Europe
Anglo-Saxon	Delivery + invoice (two-step)	UK, US, Australia

In v17/v18 this was a company toggle: Accounting → Settings → Use Anglo-Saxon Accounting. In v19 it was removed entirely by a single refactor commit.

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The Commit

08b62a4bbcc6f9a391b2cc00a621ef4c76100229
Author: amoyaux — August 9, 2025
Title:  [REF] stock_account: New inventory valuation
Files:  220 changed

Official message:

• Real-time valuation only at invoice/bill posting (removed valuation at delivery/receipt)
• Elimination of input/output interim accounts
• Removed stock.valuation.layer — value now stored on stock.move
• New product.value model for manual adjustments only
• Value priority: manual > invoice/bill > PO/SO > standard price

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What Changed Per Version

v17/v18 — Anglo-Saxon fully functional

• anglo_saxon_accounting boolean on res.company gates 3 behaviours:
  1. COGS journal lines on customer invoices (via stock_output interim account)
  2. Purchase bill lines redirected to stock_input interim account
  3. Reconciliation between interim account lines at invoice posting
• stock.valuation.layer (SVL) created on every _action_done() — tracks value, links to journal entry
• Journal entries fire at both delivery and receipt

v19 — Anglo-Saxon stripped

• stock.valuation.layer completely removed
• anglo_saxon_accounting field still exists on res.company but controls nothing
• No journal entry at delivery or receipt
• COGS always active via display_type='cogs' lines — no flag gate
• Accounts moved from product to location (location_id.valuation_account_id)

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The Core Architecture Difference

v18 Flow

stock.move._action_done()
    → stock.valuation.layer created  (product, qty, value, stock_move_id, account_move_id)
    → svl._validate_accounting_entries()
        → stock.move._account_entry_move()  →  account.move posted  ← fires at delivery
        → if anglo_saxon_accounting:
              invoices._stock_account_anglo_saxon_reconcile_valuation()

v19 Flow

stock.move._action_done()
    → stock.move._set_value()       ← FIFO / AVCO / Standard computed here
    → stock.move._create_account_move()
        → _should_create_account_move()
        → _get_account_move_line_vals()  ← accounts from location, not product
        → account.move posted            ← fires at invoice, NOT delivery

Journal Entry Comparison

Event	v18 (Anglo-Saxon ON)	v19 (always)
Goods receipt	DR Stock Valuation / CR Stock Input	nothing
Customer delivery	DR Stock Output / CR Stock Valuation	nothing
Vendor bill	DR Stock Input / CR AP + reconcile	DR Stock Valuation / CR AP
Customer invoice	DR COGS / CR Stock Output + reconcile	DR COGS / CR Stock Valuation

The interim accounts are the mechanism. No interim = no Anglo-Saxon.

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Product Category Costing — How It Affects Valuation

Two fields on product.category control everything:

property_cost_method = Selection(['standard', 'fifo', 'average'], company_dependent=True)
property_valuation   = Selection(['manual_periodic', 'real_time'],  company_dependent=True)

Cost Method	Valuation	Journal fires	COGS basis
Standard	manual_periodic	Never	Manual closing
Standard	real_time	Invoice posting	standard_price
AVCO	real_time	Invoice posting	Current rolling average
FIFO	real_time	Invoice posting	Consumed layer cost

_should_create_account_move() gates on product.valuation == 'real_time' — manual_periodic products never generate automatic journals.

AVCO and FIFO risk: In v19, COGS is computed at invoice time using the current average or FIFO state. If a new receipt arrived between delivery and invoice, the value will differ from what was on the delivery. With Anglo-Saxon interim accounts, this mismatch leaves the interim account unreconciled. Value must be locked at delivery time.

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What Was Deleted — Exact Inventory

Every item below was confirmed by reading the v18 source and the commit diff.

Accounts (from generic COA)

"stock_in",  "Stock Interim (Received)",  "1102", asset_current, reconcile=True
"stock_out", "Stock Interim (Delivered)", "1103", asset_current, reconcile=True

Fields on product.category

property_stock_account_input_categ_id   # Many2one account.account, company_dependent
property_stock_account_output_categ_id  # Many2one account.account, company_dependent

Keys removed from _get_product_accounts() on product.template

stock_input and stock_output keys no longer returned. Every downstream call to accounts['stock_input'] now fails silently or KeyErrors.

Methods deleted from product.product

• _stock_account_get_anglo_saxon_price_unit(uom) — UOM-aware standard price for COGS lines
• _create_fifo_vacuum_anglo_saxon_expense_entries(vacuum_pairs) — handles negative stock at delivery time (FIFO vacuum): if product delivered while out of stock, then received at a different price, creates a correcting expense entry and reconciles stock_output

Methods deleted from account.move

• _stock_account_prepare_anglo_saxon_out_lines_vals() — builds COGS line pairs using stock_output interim (replaced by _stock_account_prepare_realtime_out_lines_vals() using stock_valuation directly)
• _stock_account_anglo_saxon_reconcile_valuation() — the full reconciliation engine, matched interim lines from delivery with COGS lines from invoice, handled exchange differences and correction layers
• _post() Anglo-Saxon branch — called prepare_anglo_saxon_out_lines_vals() then reconcile_valuation()

Methods deleted from account.move.line

• _compute_account_id() purchase branch — redirected vendor bill lines to stock_input when Anglo-Saxon ON
• _stock_account_get_anglo_saxon_price_unit() — for credit notes, reads price from original invoice COGS line instead of current standard price

Methods deleted from stock.move

• _account_entry_move() — generated journal entry vals (now replaced by _create_account_move())
• _prepare_anglosaxon_account_move_vals() — dropship-specific Anglo-Saxon entries
• _generate_valuation_lines_data() — built debit/credit line dicts
• _get_src_account() / _get_dest_account() — account selection per move direction

Entire model removed

stock.valuation.layer — the table, the model, all methods, and stock_valuation_layer_ids on account.move.

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OCA Research

Checked all OCA repositories on 19.0 branch:

Repo	Module	Verdict
account-financial-tools	account_usability	Shows the toggle in CE UI only — zero functional restore
stock-logistics-workflow	stock_move_valuation_usage	Tracks FIFO layer sources, no COGS/reconciliation
All others	—	Nothing relevant

No OCA module restores Anglo-Saxon in v19. The gap is open.

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Module Strategy

Use the Same Model Name: stock.valuation.layer

Yes — recreate it with the same _name. Reasons:

1. _stock_account_anglo_saxon_reconcile_valuation() references stock_valuation_layer_ids by name — same model name means minimal adaptation
2. v19 fresh install has no stock_valuation_layer table — zero collision
3. Clean upgrade path: if Odoo officially restores Anglo-Saxon, uninstall the module, done
4. Developer familiarity — anyone from v15–v18 knows the name

But keep it lean — the old SVL had 20+ fields and owned FIFO stack logic. v19’s stock.move._set_value() already computes the correct value. The new SVL just records it and links delivery to journal entry.

class StockValuationLayer(models.Model):
    _name = 'stock.valuation.layer'
    _description = 'Stock Valuation Layer (Anglo-Saxon Bridge)'
    _order = 'create_date, id'

    product_id      = fields.Many2one('product.product', required=True, index=True)
    company_id      = fields.Many2one('res.company', required=True)
    description     = fields.Char()
    quantity        = fields.Float(digits='Product Unit of Measure')
    value           = fields.Monetary(currency_field='currency_id')
    currency_id     = fields.Many2one('res.currency', related='company_id.currency_id')
    stock_move_id   = fields.Many2one('stock.move', index=True)    # delivery
    account_move_id = fields.Many2one('account.move', index=True)  # delivery journal

Non-Invasive Design Rule

Every override must fall through to super() when the flag is OFF:

def any_override(self, ...):
    if not self.company_id.anglo_saxon_accounting:
        return super().any_override(...)   # pure standard v19
    # Anglo-Saxon logic

No try/except. No logic before the guard. Standard Odoo runs unchanged.

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Implementation Plan

Module Structure

custom_stock_anglo_saxon/
├── models/
│   ├── stock_valuation_layer.py     # lean SVL bridge model
│   ├── res_company.py               # restore anglo_saxon_accounting as functional
│   ├── product_category.py          # restore stock_input / stock_output fields
│   ├── product_template.py          # restore _get_product_accounts() keys
│   ├── product_product.py           # restore _stock_account_get_anglo_saxon_price_unit()
│   │                                #         _create_fifo_vacuum_anglo_saxon_expense_entries()
│   ├── stock_move.py                # hook _action_done() → create SVL + delivery journal
│   │                                # restore _prepare_anglosaxon_account_move_vals() (dropship)
│   ├── account_move.py              # restore stock_valuation_layer_ids field
│   │                                # restore _post() Anglo-Saxon branch
│   │                                # restore _stock_account_prepare_anglo_saxon_out_lines_vals()
│   │                                # restore _stock_account_anglo_saxon_reconcile_valuation()
│   └── account_move_line.py         # restore _compute_account_id() purchase branch
│                                    # restore _stock_account_get_anglo_saxon_price_unit()
├── data/
│   └── account_data.xml             # Stock Interim (Received) + (Delivered) accounts
└── views/
    ├── product_category_views.xml   # stock_input / stock_output fields on form
    └── res_config_settings_views.xml

Build Order

1. Company flag + category accounts + COA data — low risk, validate config first
2. Lean SVL model — just the fields, no logic yet
3. _get_product_accounts() keys restored — unblocks all downstream methods
4. Delivery journal entries (Standard + AVCO first, FIFO after)
5. Test Standard + AVCO purchase/sale flows
6. FIFO value-lock — store value on SVL at delivery, use it at invoice time
7. COGS line account override — stock_valuation → stock_output
8. Reconciliation engine — adapt v18’s _stock_account_anglo_saxon_reconcile_valuation()
9. Returns + credit notes
10. Multi-currency exchange difference handling
11. Dropship exclusion
12. Period-end closing compatibility audit
13. Full test suite

Do not go live on FIFO before step 6 is complete and tested.

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Risk Assessment

Risk	Severity	What breaks	Fix
Partial delivery + partial invoice	Very High	Qty mismatch → dangling interim lines	Proportional reconciliation by move
FIFO value drift (receipt between delivery and invoice)	Very High	Interim never zeros	Lock value at delivery on SVL
AVCO average shifts between delivery and invoice	High	Same as FIFO drift	Same fix — use SVL value at invoice
Returns in wrong order	High	Unreconciled credit note lines	Override _reverse_moves()
Multi-currency exchange difference	High	Reconcile fails on FX mismatch	Add exchange diff handling before reconcile
Dropship (no physical delivery)	Medium	Interim credit with no debit	Skip Anglo-Saxon for is_dropship moves
v19 period-end closing reports	Medium	Double-counting delivery journals	Audit closing queries, exclude interim entries
Landed costs after delivery	Medium	SVL value stale vs adjusted cost	Recompute SVL on landed cost posting

The critical adaptation: _stock_account_anglo_saxon_reconcile_valuation() references stock_valuation_layer_ids on account.move. In v19 that field/relation is gone. Must replace with stock_move_ids lookups — this is the single hardest rewrite in the project.

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Test Matrix

Run every row for Standard, AVCO, and FIFO separately. All must pass before go-live.

Purchase flows

• PO → full receipt → full bill
• PO → partial receipt → bill → remaining receipt → remaining bill
• PO → receipt → bill at higher price (price difference account)
• PO → receipt → vendor return → credit note
• Dropship PO

Sale flows

• SO → full delivery → full invoice
• SO → partial delivery → invoice → remaining delivery → remaining invoice
• SO → delivery → customer return → credit note
• SO → delivery → invoice → return → credit note (reversed order)
• Dropship SO

Special cases

• FIFO vacuum — deliver while out of stock, receive later at different price
• AVCO receipt between delivery and invoice shifts average
• Standard price change while stock on hand
• Multi-currency (delivery rate ≠ invoice rate)
• Landed cost applied after delivery but before invoice
• Period-end closing report — no double-counting

After every test, verify:

-- Interim accounts must net to zero after reconciliation
SELECT SUM(debit) - SUM(credit) AS balance
FROM account_move_line
WHERE account_id IN (<stock_input_id>, <stock_output_id>)
  AND reconciled = TRUE;

-- No unreconciled lines older than 30 days
SELECT COUNT(*) FROM account_move_line
WHERE account_id IN (<stock_input_id>, <stock_output_id>)
  AND reconciled = FALSE
  AND date < NOW() - INTERVAL '30 days';

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Effort

Task	Days	Risk
Config (flag, accounts, category fields)	1	Low
Lean SVL model	0.5	Low
Delivery journal entries (Standard + AVCO)	2	Medium
FIFO value-lock mechanism	2	Very High
COGS account override	1	Medium
Reconciliation engine adaptation	3	Very High
Returns / credit notes	2	High
Multi-currency	2	High
Dropship exclusion	0.5	Low
Period-end closing audit	2	High
Test suite	5	—
Total	~21 days	Senior dev, knows both v18 and v19