Bookkeeping checklist for ZZP freelancers in the Netherlands (2026)

What does a compliant bookkeeping system include for a Dutch freelancer (ZZP) in 2026?

To stay compliant in 2026, a Dutch freelancer (ZZP) must keep a business administration (administratie) that allows the Tax Administration (Belastingdienst) to check taxes within a reasonable time. Core bookkeeping records must be kept for 7 years, and some VAT records must be kept for 10 years (for example, immovable property and certain One Stop Shop records). Keep documents in the original form (digital stays digital).

Browse the [Knowledge Hub](/knowledge-hub) for more freelancer accounting guides. A 2026 bookkeeping setup should let a freelancer prove every euro of income and cost with a document and a matching payment. The administration must show an audit trail from source document (invoice/receipt) to bank transaction to totals used in VAT return (BTW-aangifte) and income tax (inkomstenbelasting).

A simple way to stay organized is to close the books every month: save bank statements, book new invoices, and mark unpaid items. If bookkeeping is done in a cloud tool or by a third party, the freelancer remains responsible for keeping data available for the full retention period. The Belastingdienst brochure on automated administration recommends clear agreements on availability and responsibilities (for example, in an SLA).

• Sales invoices with sequential invoice numbers (no duplicates) and a delivery date when relevant.
• Purchase invoices and receipts (bonnen), plus proof of payment (bank transaction).
• Bank statements and payment references that link to each invoice line.
• A debtor and creditor list (open invoices) at least once per quarter.
• Contracts, subscriptions, and business correspondence that explains the business purpose of costs.
• Asset and investment records (purchase, use date, and depreciation schedule) kept for 7 years.
• VAT-specific records kept for 10 years when the law requires it (for example, immovable property or OSS records).

Which invoice fields are mandatory in the Netherlands in 2026?

A standard Dutch VAT invoice in 2026 must include fields such as the supplier and customer names and addresses, the supplier's VAT identification number (btw-id), the invoice date, and a unique invoice number in a sequential series. If the total invoice amount is at most €100 (including VAT), a simplified invoice is allowed with fewer fields. For B2B supplies, invoices are generally sent by the 15th day of the following month.

Missing invoice fields can block VAT reclaim on business costs, so keep a checklist and fix supplier invoices quickly (ideally within 7 days of receipt). For example, an invoice number must be unique within a series and the supplier's btw-id must be present. For how to document business costs in practice, see the [deductible expenses guide](/knowledge-hub/deductible-expenses-freelancers-netherlands/).

Invoices are part of the business administration and must be kept in the form in which they were sent or received. Digital invoices must be stored digitally. Paper receipts can be scanned and stored digitally if the scan is a complete and accurate copy. A simplified invoice can be used for small amounts up to €100 (including VAT), but it still needs the issue date, supplier details, what was supplied, and the VAT.

• Supplier legal name and full address, and customer legal name and full address.
• Supplier VAT identification number (btw-id) with country code (NL...).
• Supplier KvK number if the supplier is registered in the Dutch Trade Register.
• Invoice issue date and a unique invoice number in a sequential series.
• Description of goods/services, quantity, and (if different) the delivery/performance date.
• VAT rate (21%, 9%, 0% or exemption reference where applicable) and the VAT amount.
• Total amount payable (including VAT) and, if relevant, any discounts or surcharges.

What are the 2026 VAT return (BTW-aangifte) deadlines for quarterly filers?

For quarterly VAT filers in 2026, both the VAT return (BTW-aangifte) and the payment must be received by: 30 April 2026 (Q1), 31 July 2026 (Q2), 31 October 2026 (Q3), and 31 January 2027 (Q4). If VAT is filed yearly, the 2026 annual return and payment are due by 31 March 2027. Missing these dates can trigger penalties and a VAT assessment.

Most freelancers file VAT per quarter. The Belastingdienst publishes the exact due dates for each quarter, and the same date applies to filing and payment. If VAT is submitted via administration or bookkeeping software, the Belastingdienst portal accepts submission from the 24th of the month before the end of the period. See the [VAT returns guide for expat freelancers](/knowledge-hub/vat-returns-netherlands-expat-freelancer-guide/) for the core boxes and common mistakes.

Start preparing VAT at least 10 days before the deadline. Reconcile bank transactions to invoices, check that the VAT rate per sale is correct (21%, 9% or 0%), and confirm that purchase invoices meet the legal invoice requirements before reclaiming input VAT. If a quarter has no sales, a nil return (nihilaangifte) is still required when the Belastingdienst expects a return for that period.

• Day -10: export bank transactions for the quarter and match every business payment to an invoice or receipt.
• Day -7: check sales invoices for correct VAT rate (21%, 9%, 0%) and correct btw-id formatting.
• Day -5: verify purchase invoices have all mandatory fields before reclaiming VAT.
• Day -3: review VAT totals per box and compare to the previous quarter for outliers (+/- 20% or more).
• Day -1: submit the VAT return and save the submission confirmation and payment reference.
• Day 0: pay VAT so that the amount is received by the Belastingdienst on the due date.

When is the 2025 income tax return due in 2026, and how do you request extension?

The 2025 income tax return (inkomstenbelasting) is usually due by 1 May 2026, based on the date in the official tax return letter (aangiftebrief). If the deadline cannot be met, request extension (uitstel) before 1 May 2026; the standard extension runs to 1 September 2026 and the Belastingdienst confirms the request within 3 weeks. Filing on time reduces the risk of reminders, penalties, and tax interest.

Income tax uses the calendar year (2025) but is filed in 2026. A freelancer should close 2025 bookkeeping before starting the return: confirm total turnover, collect all deductible cost invoices, and ensure business and private costs are separated. If deductions are claimed, the freelancer must keep evidence in the administration for 7 years, including invoices, receipts, and payment proof.

An extension changes the filing deadline, not the bookkeeping requirements. If a freelancer files together with a fiscal partner, each person must request extension separately unless a formal authorization is in place. The Belastingdienst answers extension requests by letter, so save the confirmation in the 2025 tax folder and use the new deadline (often 1 September 2026) as the planning anchor.

• By February 2026: ensure the 2025 invoice sequence has no gaps or duplicates and that all invoices have a delivery date when required.
• Before 1 May 2026: file the 2025 income tax return, or request extension before 1 May 2026.
• By 1 September 2026 (if extended): submit the income tax return and save the confirmation PDF.
• Keep a 7-year archive for 2025: invoices, receipts, bank statements, and contracts that support deductions.
• Check VAT returns for 2025 against bookkeeping totals before finalizing the income tax profit figure.
• Store the 2025 profit-and-loss summary and supporting exports in a format that can be reproduced later.

What penalties apply if you miss a VAT return or payment deadline in 2026?

Missing a VAT deadline can create two separate penalties in 2026: one for filing and one for paying. A late or missing VAT return usually triggers a €82 filing penalty, and repeat cases can be penalized up to €165 per return. A late VAT payment triggers a 3% penalty (minimum €50, maximum €6,709). If late payment happens often, the rate can be raised up to 10%, capped at €6,709 per year.

If a freelancer misses a VAT deadline, submit the VAT return in Mijn Belastingdienst Zakelijk as soon as possible and pay the VAT due using the correct payment reference. Save the submission confirmation and the bank payment proof in the VAT folder for the year. Fast action reduces the chance of repeat penalties and keeps the bookkeeping archive complete for the 7-year retention period.

What happens if you file the income tax return late (or not at all) in 2026?

If an income tax return is late in 2026, the Belastingdienst can send a reminder and then a demand (aanmaning). After the aanmaning, the return must be received within 10 working days. Filing after that can trigger a €469 administrative penalty (verzuimboete), which can rise to €6,709 for repeat late filing. If no return is filed, the Belastingdienst estimates the income and issues an assessment. Income tax interest is 5% from 1 January 2026.

If a freelancer is late, submit the return as soon as possible, even if some amounts are estimates, and correct later if needed through the available correction route. Keep the full 7-year evidence package (invoices, bank statements, and contracts) ready for questions, because late filing increases the chance of follow-up. Use the aanmaning date to count the 10 working days and avoid triggering the €469 penalty.