Finnish companies that invoice other businesses cannot get away with a plain PDF anymore. Trading partners and public buyers expect a structured Finvoice 3.0 e-invoice, every domestic payment slip needs a valid viitenumero reference number and a scannable bank barcode, and the books have to follow the account structure and ALV VAT logic expected under kirjanpitolaki. Odoo core gives you account, account_edi, base_vat and base_iban as raw building blocks, but out of the box it ships neither a Finnish chart of accounts, nor the 25.5/14/10/0% ALV rate set with domestic reverse charge, nor the reference-number and barcode standards, nor a Finvoice XML mapping. A typical off-the-shelf apps.odoo.com module usually covers one slice — a chart template, or a bare e-invoice export — and leaves the reference numbers, barcodes, operator handoff and inbound bill capture for you to bridge by hand.

We build a single, coherent Finnish localization on top of the native accounting engine so those gaps close together. The chart of accounts is delivered as an account.chart.template aligned to kirjanpitolaki practice, with the ALV rate set (25.5%, 14%, 10%, 0% and domestic reverse charge) wired as account.tax records and grouped through tax tags into an ALV VAT-return summary mapping so the periodic return foots correctly. Reference-number generation follows the Finnish viitenumero standard (base number plus 7-3-1 weighted check digit) as a compute/@api.depends field on account.move, and the bank barcode (virtuaaliviivakoodi) is rendered directly onto the invoice through an extended QWeb report so customers can pay by scanning. Y-tunnus business-ID validation extends base_vat, and OVT/EDI identifiers are stored and validated on res.partner for correct operator routing.

The Finvoice 3.0 layer is where the real engineering sits. Sales invoices are serialized to compliant Finvoice 3.0 XML through an account_edi format, mapping seller/buyer parties, OVT identifiers, line items, ALV breakdown, the reference number and the EpiDetails payment block. Sending happens either by operator handoff to a service-operator gateway (the widely-used Maventa/Apix-style web-service pattern) or by a monitored file drop, driven by an automated action so approved invoices flow out without manual export. Inbound Finvoice files are parsed and matched back to purchase orders and partners to create draft vendor bills for review — closing the loop on receiving as well as sending. For payments, we add SEPA / Finnish bank payment-file (pain.001) generation so supplier runs leave Odoo in the format your bank expects. Everything is exposed to the standard XML-RPC/JSON-RPC API and secured with ir.model.access.csv plus record rules, and it is built and tested against Odoo 17.0, 18.0 and 19.0 on both Community and Enterprise (Enterprise's document/EDI conveniences are used where present, with a Community-safe fallback).

Because this is build-to-order, nothing ships until we have agreed the scope on a short call: which operator you use, your ALV filing pattern, whether you need inbound capture and payment files, and any chart customizations. Typical delivery is one working week from confirmed scope. You receive installable source for your Odoo version, a UAT pass on a staging copy of your database with a rollback plan, and a post-go-live support window. Pricing starts from $999 (indicative, single-company base scope); multi-company groups, additional operator integrations, inbound-bill automation depth and historical data migration volume increase the quoted scope, and the fixed quote is confirmed only after the scoping call.