Sri Lanka VAT Invoice Compliance

v 19.0 Third Party 5

Availability	Odoo Online Odoo.sh On Premise
Odoo Apps Dependencies	• Invoicing (account) • Discuss (mail)
Lines of code	1043
Technical Name	`l10n_lk_vat`
License	LGPL-3
Website	https://www.beaver-hub.com

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Availability	Odoo Online Odoo.sh On Premise
Odoo Apps Dependencies	• Invoicing (account) • Discuss (mail)
Lines of code	1043
Technical Name	`l10n_lk_vat`
License	LGPL-3
Website	https://www.beaver-hub.com

Sri Lanka VAT Invoice Compliance l10n_lk_vat

Gazette-exact Tax Invoice, Tax Credit Note and Tax Debit Note for Odoo 19 – implementing the format mandated by the Commissioner General of Inland Revenue, Sri Lanka, effective 1 January 2026.

LGPL-3 · Free Odoo 19 IRD Gazette No. 2481/22 Tax Invoice Credit Note Debit Note YYMMM_QQQQ_XXXXX COPY ONLY Reprint

Overview

Description

l10n_lk_vat adds gazette-compliant invoicing to Odoo 19 for businesses registered under the Value Added Tax Act, No. 14 of 2002, Sri Lanka. It implements the complete "Tax Invoice Specification" (Annexure I) published in the Extraordinary Gazette notification No. 2481/22, Friday, March 27, 2026 (effective 1 January 2026), covering all supplier obligations.

Every customer invoice, credit note and debit note gets an auto-generated gazette serial number in YYMMM_QQQQ_XXXXX format, and the printed A4 PDF switches its title and layout to TAX INVOICE, TAX CREDIT NOTE or TAX DEBIT NOTE automatically based on document type.

The module is per-company: a single Odoo database can have Sri Lanka VAT–enabled companies alongside companies that use standard Odoo invoicing, with zero cross-contamination.

Free and open-source under LGPL-3. Built by Beaver Hub (Pvt) Ltd as a community contribution to Sri Lanka's Odoo ecosystem.

Legal basis: Value Added Tax Act, No. 14 of 2002; Extraordinary Gazette No. 2481/22, Friday, March 27, 2026; Annexure I - "Tax Invoice Specification". Effective date: 01 January 2026. Official source: ird.gov.lk/en/publications/sitepages/Gazette.aspx

Gazette clauses covered

Unit tests

Document types

Screenshots

Product Screenshots

Tax Invoice - Gazette-Compliant A4 PDF

Prints YYMMM_QQQQ_XXXXX serial at the top, all required IRD fields in independently boxed sections, dates in MM/DD/YYYY format, total in words, and a true repeating page footer with page numbers.

Tax Credit Note - Gazette-Compliant A4 PDF

Same gazette layout with title auto-switched to TAX CREDIT NOTE. Additionally prints Original Invoice No. and Original Invoice Date for full traceability. Independent serial counter from Tax Invoices.

Tax Debit Note - Gazette-Compliant A4 PDF

Same gazette layout with title auto-switched to TAX DEBIT NOTE. Prints Original Invoice No. and Date from the originating invoice. Independent serial counter from Tax Invoices and Credit Notes.

Copy Invoice - COPY ONLY Stamped PDF

Reprint of any posted Tax Invoice, Credit Note or Debit Note. Identical to the original but overlaid with a red circular "COPY ONLY" stamp. Original serial number is preserved - no new number consumed. Requires a mandatory reason before printing.

Settings - Sri Lanka VAT Compliance

Per-company kill switch in Accounting settings. The "Configure VAT Invoice Layout" button opens the three-tab wizard directly - no code changes, no restarts.

VAT Layout Designer Wizard - 3 Tabs

Layout: template selector, logo on/off, VAT rate. Signature: signatory name, designation, wet-signature box toggle. Footer: free text - bank details, payment terms.

Gazette Compliance

IRD Gazette Requirements Implemented

Maps every IRD obligation to the concrete module implementation.

IRD Requirement	Module Implementation
Document prominently titled "Tax Invoice" (or Credit/Debit Note)	Bold bordered title box - auto-switches to TAX CREDIT NOTE / TAX DEBIT NOTE by document type
Supplier TIN, name, address, telephone - top-left	Rendered from `res.company`: VAT/TIN, name, address, phone
Purchaser TIN, name, address, telephone - top-right	Rendered from invoice's `partner_id`: name, address, VAT, phone
Invoice serial number - `YYMMM_QQQQ_XXXXX`, ≤40 chars, no spaces	Custom `sequence.mixin` override - monthly reset, isolated per document type and journal unit code
Date of Invoice - MM/DD/YYYY	Formatted via `strftime('%m/%d/%Y')` in QWeb report
Place of Supply	New field `l10n_lk_place_of_supply` on `account.move` - defaults to company city, editable per invoice in draft
Date of Delivery - MM/DD/YYYY	Odoo's native `taxable_supply_date` field surfaced, formatted MM/DD/YYYY
Description of supply, quantity, unit of measure	Standard Odoo invoice lines: `name`, `quantity`, `product_uom_id`
Value of Supply - net, VAT amount, total, total in words - stated in LKR with cents (2 decimal places), per the gazette amendment	Total Value of Supply, "VAT Amount @ 18%", Total incl. VAT, amount in words (optional, on by default) - shown at full precision, matching the line items, no rounding applied
Mode of Payment	New selection field `l10n_lk_mode_of_payment` - 7 gazette-defined options
Additional information of the supply	Free-text box using the invoice's `narration` / notes field
Supplier must retain a duplicate; reprints must be clearly marked and auditable	"Print Copy" wizard: mandatory reason, red "COPY ONLY" stamp on PDF, `l10n_lk_copy_count` counter, permanent chatter log

Module Features

Core Features

Gazette Serial Number Generator

Format YYMMM_QQQQ_XXXXX - ≤40 chars, no spaces
Monthly counter reset (prefix changes with YYMMM)
Counter isolated per document type - invoices, credit notes and debit notes each have their own independent sequence
Journal-level QQQQ unit code configurable per branch/department
Sequence prefix derived from invoice date, not posting date

Dedicated Gazette Print Layout

Completely separate QWeb template - does not use web.external_layout
Independently boxed supplier (left) and purchaser (right) sections
True repeating page footer with page numbers (Page X of Y)
Auto-switches title: TAX INVOICE / TAX CREDIT NOTE / TAX DEBIT NOTE
Optional authorised signatory box at bottom for wet signature
Red circular "COPY ONLY" stamp for reprints

wkhtmltopdf UTF-8 Rendering Fix

Patches ir.actions.report._build_wkhtmltopdf_args() to force --encoding utf-8
Eliminates the known Qt mojibake bug: ftÂ³ → ft³
Requires the patched-Qt build of wkhtmltopdf (0.12.5 recommended by Odoo)

Flexible Per-Invoice Print Format

For purchasers who are not VAT-registered, a Tax Invoice is not the correct document - this toggle switches that specific invoice to Odoo's standard layout instead
Boolean toggle l10n_lk_print_as_tax_invoice on every invoice, default On
Off falls back to Odoo's standard invoice layout for that document only
Single source of truth for the Print button, the cog-wheel Print menu, and the Send & Print wizard
Never touches Odoo's global "Invoice PDF" action - other companies in the same database are unaffected
Does not affect the gazette serial number - numbering stays governed solely by the kill switch

COPY ONLY Reprint Audit Trail

"Print Copy" button visible only on posted documents
Opens wizard - reason is mandatory before printing
Increments l10n_lk_copy_count (read-only on invoice form)
Posts permanent chatter message: user, timestamp, reason, copy number
PDF retains original sequence number - no new number consumed
Does not re-trigger accounting entries or touch related documents

VAT Layout Designer Wizard

Accessed via Settings → Sri Lanka VAT Compliance → "Configure VAT Invoice Layout"
Layout tab: show/hide company logo (gazette format does not require it), VAT rate, show/hide total amount in words
Signature tab: signatory name, designation, blank signature box toggle
Footer tab: free text - bank details, payment terms, etc.
All settings stored on res.company - apply immediately to next print

Company-Level Kill Switch

l10n_lk_vat_enabled boolean on res.company
When False: gazette numbering and layout fully bypassed - standard Odoo invoicing unchanged
Safe to install on multi-company databases where only some entities are LK VAT registered
Per-company configuration - no global settings

Code Quality & Testing

76 unit tests using AccountTestInvoicingCommon, tagged post_install
Covers: sequence generation, monthly reset, counter isolation, copy guards, field defaults, print-toggle redirects, wizard write-through
pylint-odoo compliant, ruff-formatted
No external Python dependencies beyond Odoo core

Serial Format

Invoice Numbering Format

Serial Format

26JAN_HEAD_00001

YY·MMM · QQQQ · XXXXX - max 40 characters, no spaces

Segment	Meaning	Example	Notes
`YY`	Last 2 digits of the invoice year	`26`	Derived from the invoice date - not the posting date
`MMM`	First 3 letters of the invoice month, uppercase	`JAN`, `JUN`	Counter resets to `00001` each time this changes
`QQQQ`	Alphanumeric branch/unit code - configured per journal	`HEAD`, `BR03`	Set on the Sales Journal (`l10n_lk_vat_unit_code`) - mandatory once LK VAT is enabled
`XXXXX`	Zero-padded numeric running counter	`00001`, `00042`	Always ≥5 digits; resets every calendar month

Counter isolation: Tax Invoices, Tax Credit Notes and Tax Debit Notes each maintain their own independent counter. The monthly reset is automatic: when YYMMM changes, the counter starts from 00001 again.

Setup Guide

Configuration

Enable VAT Compliance for a Company

Settings → Invoicing/Accounting → Sri Lanka VAT Compliance

Toggle "Enable Sri Lanka VAT Compliance" on. This is a per-company field - other companies in the database are unaffected until you enable it for them too.

Note: this is a per-company switch, not a database-wide setting Running multiple companies in one Odoo database? Each company has its own "Enable Sri Lanka VAT Compliance" toggle. Switch to a company in the top-right company selector before repeating Step 1 for it - only companies you explicitly enable will print the gazette Tax Invoice format and use YYMMM_QQQQ_XXXXX numbering. Every other company keeps printing Odoo's standard invoice, completely unaffected.

Accounting → Configuration → Journals → set "VAT Unit Code (QQQQ)"

Open each Sales journal and set the VAT Unit Code (e.g. HEAD, BR03). This field is mandatory - Odoo will block saving the journal without it.

Settings → Sri Lanka VAT Compliance → "Configure VAT Invoice Layout"

Opens the three-tab wizard. Layout: show/hide logo. Signature: signatory name, designation, blank signature box toggle. Footer: free text printed in the repeating page footer - use for bank details or payment terms.

Per-Invoice Fields

On each draft customer invoice: Place of Supply & Mode of Payment

Place of Supply: defaults to company city; edit if the delivery origin differs. Mode of Payment: select from Cash, Bank Transfer, Cheque, Credit Card, Debit Card, Mobile Payment, or Online Payment. Both are locked once the invoice is confirmed. Print as Tax Invoice: on by default - turn off when the purchaser is not VAT-registered and a Tax Invoice is not the correct document, to print Odoo's standard layout instead. Editable at any time.

Issuing a COPY ONLY Reprint

Open a posted invoice → click "Print Copy"

A wizard opens - enter a mandatory reason. Click Print Copy. The PDF is generated with the original sequence number unchanged but with a red "COPY ONLY" stamp. The copy counter increments and a permanent chatter message records the event. No new accounting entries, no new sequence number consumed.

Technical

Requirements & Installation

Odoo & Python

Odoo version: 19.0 (Community or Enterprise)
Python: no additional pip packages - Odoo core only

Module Dependencies

account - invoicing base
account_debit_note - provides "Add Debit Note" action
l10n_lk - Sri Lanka chart of accounts localization

System Dependency

wkhtmltopdf - already required by Odoo for any PDF report
Recommended: wkhtmltopdf 0.12.5 with patched Qt (Odoo's recommended build)
The module's UTF-8 fix patches the args - if you still see garbled characters, confirm the binary version

Installation

Copy l10n_lk_vat/ into your addons_path
Restart Odoo or update the apps list
Search for "Sri Lanka VAT Invoice Compliance" in Apps → Install
Configure as described above - no demo data or default sequences are created on install

Running the Test Suite

All tests are tagged post_install. Use -u (update) to trigger them - -i (install) is a no-op when the module is already installed.

# Run all module tests

./odoo-bin -d <database> --test-enable --test-tags l10n_lk_vat -u l10n_lk_vat --stop-after-init

# Run a specific test file

./odoo-bin -d <database> --test-enable --test-tags /l10n_lk_vat/tests/test_sequence.py -u l10n_lk_vat --stop-after-init

# Run a single test class

./odoo-bin -d <database> --test-enable --test-tags /l10n_lk_vat/tests/test_copy.py:TestL10nLkCopy -u l10n_lk_vat --stop-after-init

# Run a single test method

./odoo-bin -d <database> --test-enable --test-tags /l10n_lk_vat/tests/test_fields.py:TestL10nLkFields.test_vat_rate_negative_raises -u l10n_lk_vat --stop-after-init

Test file	What it covers
`tests/test_sequence.py`	Gazette sequence format, monthly reset, counter isolation per document type
`tests/test_copy.py`	COPY ONLY counter, wizard guards, copy-mode context bypass security fix
`tests/test_fields.py`	Field defaults, VAT rate constraints, journal unit-code constraint, wizard write-through
`tests/test_printing.py`	Print-as-Tax-Invoice toggle redirect at the Print button, report_action(), and the cog-wheel/Send wizard chokepoint

Tip: use a throwaway database (e.g. -d test_mydb) so test data does not pollute your production instance.

Uninstall warning: uninstalling after invoices have been posted will drop the custom fields (l10n_lk_place_of_supply, l10n_lk_mode_of_payment, l10n_lk_copy_count, etc.) and their historical data. To revert a single company to standard invoicing without uninstalling, simply disable the kill switch.

Troubleshooting

Known Issues & Troubleshooting

Garbled characters in PDF (ftÂ³ instead of ft³) Known wkhtmltopdf/Qt bug where locally-loaded HTML is mis-detected as Latin-1. This module patches ir.actions.report._build_wkhtmltopdf_args() to force --encoding utf-8. If you still see corrupted characters, confirm your wkhtmltopdf binary is the patched-Qt build (version 0.12.5).

Journal save fails with "A VAT Unit Code (QQQQ) is required" Set the Unit Code on the Sales journal (Accounting → Configuration → Journals → open the sales journal → set VAT Unit Code) before saving. Mandatory for any Sales journal once VAT compliance is enabled.

Sequence shows the wrong month prefix The sequence prefix is derived from the invoice date, not the date of the previous invoice. Check that the invoice's invoice_date is correct before posting - the prefix is locked in at the moment of sequence assignment.

Changelog

Release Notes

19.0.1.0.0 June 2026 Initial Release

Gazette YYMMM_QQQQ_XXXXX serial number - auto-assigned on post, monthly reset, scoped per journal unit code
Full A4 QWeb PDF report - Tax Invoice, Tax Credit Note, Tax Debit Note with all IRD-required fields
LKR totals shown with cents (2 decimal places), per the amended Clause 4.1.g
Total amount in words - optional, toggleable per company (on by default)
Repeating page footer with page numbers on every printed page
Red COPY ONLY circular stamp on reprints (Clause 6.2)
Original invoice reference block on Credit Notes and Debit Notes

Three-tab VAT Layout Designer wizard - logo, VAT rate, signatory, footer text, total-in-words visibility
Place of Supply field - defaults to company city, editable per invoice (Clause 4.1.c)
Mode of Payment - seven gazette-specified options (Clause 4.1.h)
Per-invoice Print as Tax Invoice toggle - one source of truth for the Print button, Print menu, and Send & Print wizard
COPY ONLY reprint audit trail - requires reason, logs to chatter, increments copy counter
Per-company kill switch - safe in multi-company databases
Global UTF-8 fix for wkhtmltopdf; 76 automated tests

Developer

About Beaver Hub

Beaver Hub (Pvt) Ltd

Odoo Partner · Sri Lanka

Beaver Hub is a Sri Lanka–based Odoo implementation and development company. We build production-ready modules focused on accuracy, maintainability, and long-term support.

l10n_lk_vat was developed directly from the IRD gazette - every field label, date convention, sequence format, and label wording is gazette-traced, not approximated. We maintain this as a free, open-source contribution to the Sri Lanka Odoo community.

beaver-hub.com github.com/Beaver-Hub-LK/odoo-srilankan-vat

For support, feature requests, or customisation inquiries: contact Beaver Hub via hello@beaver-hub.com. Free community support is provided via GitHub Issues.

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Web & Email

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Beaver Hub (Pvt) Ltd - Sri Lanka | beaver-hub.com

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