Standard Audit File for Tax (SAF-T) became mandatory in Norway from 1 January 2020. Every bookkeeping-liable company must be able to deliver a SAF-T file on request from the Tax Administration within 14 days. This guide walks through what the mandate requires, which fields the file must contain, and how to ensure the file passes XSD validation on the first try.
SAF-T is an OECD standard for exporting accounting data in a standardized XML format. Norway was the first country in Europe to fully mandate it for all bookkeeping-liable companies in 2020. The purpose is to make audits faster and reduce asymmetry between taxpayer and authority. The SAF-T file does not replace the books — it is an export form.
Seven main structures: Header (company info + period), MasterFiles (chart of accounts NS 4102, customers, vendors, VAT codes), GeneralLedgerEntries (vouchers with postings), SourceDocuments (invoice references), Movement of Goods (inventory if applicable), Working Documents (bridge between MasterFiles and GL), Audit File Version. Each record must have a unique ID and be referenced correctly.
Once requested by Skatteetaten you have 14 days. Delivery happens either via Altinn (form RF-1346 with XML attachment) or as encrypted files on USB/disk if size exceeds 100 MB. The file must be signed with an eIDAS-compliant digital signature — usually BankID for persons or a business certificate.
Top 5 errors in SAF-T submissions: (1) VAT code mapping fails — the file uses NS 4102, not the company's internal codes, so mapping must be done. (2) Missing opening balance for the year — all GL accounts must have a starting balance. (3) Invalid org.nr for customers/vendors — the check digit must pass modulo 11. (4) Vouchers that do not balance — debit + credit must net to zero. (5) Timestamps in local zone — Skatteetaten requires UTC.
Talk to us about how the 4b2b ecosystem fits into your existing Altinn process. We have implementations from 50-employee firms to OBX-listed companies.
