Auditfile Financieel (XAF): the Dutch audit file explained

If you are a freelancer with business in the Netherlands, your bookkeeper (boekhouder) or the Dutch tax administration may ask for an auditfile. It sounds technical, but the idea is simple: one standard file that contains your accounting data, so nobody has to dig through spreadsheets or printouts.

What the Auditfile Financieel is

The XML Auditfile Financieel (XAF) is a standard file format the Belastingdienst developed together with SRA and accounting software vendors. It holds most of the data a tax inspection needs, and most Dutch bookkeeping packages support it, usually as a menu option (Belastingdienst, as of October 2026). The XAF is one of a family of Dutch auditfiles (others cover payroll, cash registers and taxi on-board computers), developed under the direction of the Auditfile-Platform, a cooperation of software vendors, professional bodies, SRA and the Belastingdienst (ODB Belastingdienst, as of October 2026).

The Belastingdienst describes the financial auditfile as an extract of the general ledger (brochure "Uw geautomatiseerde administratie en de fiscale bewaarplicht", July 2026). According to the Belastingdienst's developer portal, the open standard serves the exchange of data from administrative systems for reporting and control, and its main users are the Belastingdienst, insolvency administrators (curatoren) and the accountancy profession (ODB, "Achtergrond informatie XAF4.0", as of October 2026).

When you need it

The auditfile is not a return and has no filing deadline. The Belastingdienst says it often asks for one during a boekenonderzoek, a books investigation (same brochure). Two points from that brochure matter:

• Keeping only the auditfile is never enough. The underlying administration must be kept as well.
• The normal fiscal retention period is 7 years, with longer periods in some cases, for example 9 years for VAT on real estate (as of July 2026).

Versions: 3.2 and 4.0

For years the common version was XAF 3.2. It was agreed in the XML Platform in February 2014, with a planned delivery date of 1 April 2014; the changes for 3.2 added, among others, change information and history for ledger accounts and customers/suppliers, bank details on transaction lines, and references to link ledger accounts to the Dutch reference chart of accounts (RGS) (XML Platform report, 19 February 2014).

Its successor, XAF 4.0, reduces the number of data fields from 250 to 90, records RGS more clearly and is meant as a base for future developments such as ViDA (ODB, "Achtergrond informatie XAF4.0", as of October 2026). The Belastingdienst announced that from 1 January 2027 only XAF 4.0 is accepted for delivery and older versions are no longer wanted; RGS only has to be included if the software already has it (ODB announcement of 22 April 2026, as of October 2026). If your bookkeeping software produces the auditfile you would hand to an inspector, check that it supports 4.0.

Structure

An auditfile is XML: structured plain text that both people and machines can read (ODB Belastingdienst, as of October 2026). The Belastingdienst publishes the technical specification as a download for software developers on its ODB portal; the current release there is XAF 4.0.3, with an XML schema (XSD), a functional specification and an explanatory note (ODB, "XML Auditfile Financieel (XAF) v4.0.3", as of October 2026). In version 4.0 a file has one header and one company block:

• Header: financial year, start and end date, currency, creation date, the software that produced the file and, optionally, the RGS version.
• Company: name, country and VAT identification number, optionally the KvK number and address.
• Master data: customers and suppliers, ledger accounts (each with its type and, optionally, its RGS code), VAT codes and periods.
• Opening balance and transactions: bookings grouped per journal; each transaction consists of lines with account, amount, debit or credit and, optionally, the VAT details.

The explanatory note adds two practical rules: an optional field must be filled whenever the data is available in the software, and the file extension is .XAF.

How a bookkeeper uses it

Because every package writes the same structure, a bookkeeper or accountant can run standard analyses on a client's data instead of rebuilding it by hand. The Belastingdienst encourages using XAF together with RGS for exactly this, and points to shared analyses such as a reconciliation of the bookkeeping with the VAT return (ODB, "Oproep tot implementeren van Auditfile financieel XAF3.2 met RGS", as of October 2026). When the Belastingdienst requests an auditfile, it is created from the accounting software that holds the complete administration.

How Bonro produces it

Bonro exports your receipts as an Auditfile Financieel 4.0 file (.xaf) for your boekhouder, built to the XAF 4.0.3 specification and tested against the XML schema the Belastingdienst publishes. The file has a header (financial year, period, currency, creation date, RGS version), a company block with the name, KvK number and VAT number you entered in Bonro, one generic supplier record, the ledger accounts used with their RGS code, one VAT code per rate, monthly periods and a single purchase journal (Inkoopboek). Each receipt becomes one balanced transaction: the expense excluding VAT on the account of its category, with the VAT rate and amount, the input VAT (te vorderen BTW) and the total on creditors, or two lines when there is no VAT. The account numbers are a starting point that your boekhouder maps to their own chart of accounts.

One honest limit: the file holds only the purchase entries from your receipts, with no opening balance and no sales or bank entries, so it is not a complete administration. It is input for your boekhouder; the auditfile for a tax inspection comes from the software that holds your full bookkeeping. For France, see the FEC guide.

The Auditfile export is part of the Bonro Pro plan; see Bonro's pricing for details.