The letter is the starting point
The duty to file does not arise from earning a certain amount but from being invited. If you receive a filing letter, you must file — even if nothing turns out to be payable. The final date is in that letter itself rather than in a general rule; it is often 1 May, but go by your own letter.
If you cannot make that date, request an extension before it passes. Anyone who receives an invitation and files late risks a penalty, and that stands apart from whether you ended up paying or being refunded.
You can be required to file without a letter
No filing letter does not automatically mean no obligation. If a return would show that you owe more than the threshold amount set for that year, you are required to file it of your own accord. Those thresholds are set annually, so look up the one for the year in question rather than working from a figure you remember.
The other way round is not a duty but an opportunity: if you would get money back, you need do nothing — but then you will not get it. That often applies to anyone who worked in the Netherlands for only part of a year, because payroll tax was calculated as if you earned that much all year.
As an entrepreneur you declare your profit here
If you are an entrepreneur for income tax — a sole trader or a share in a partnership — there is no separate "business return". Your profit from the business is part of your ordinary income tax return, in box 1, alongside for instance wages from a job you hold on the side.
The entrepreneur deductions belong there too, and they hang on the hours criterion of 1,225 hours. So sound bookkeeping is not only a retention duty: it is the evidence for both your profit and your deductions in the same return.
Step by step: your return as an entrepreneur
Step 1: close your financial year. As an entrepreneur your return has two parts: a private part, which everyone fills in, and a business part with your profit and loss account and your balance sheet. For that second part you need figures only your records know: your turnover excluding VAT, your purchases, depreciation on your business assets and your business expenses, and on the balance sheet among other things your unpaid invoices and your bank and cash balance on 31 December.
Step 2: log in to Mijn Belastingdienst, the personal portal of the Dutch Belastingdienst; your income tax return is ready there. Step 3: fill in the private part and enter your profit and loss account and balance sheet in the business part. The entrepreneur's deductions belong there too, such as the self-employed deduction if you meet the hours criterion. Step 4: check the calculation and submit before the date in your letter — or request an extension before then.
In booxx the profit and loss account and balance sheet of your financial year are under Reports, with a link through to the entries behind them. During the year, IB & Zvw reservation shows roughly how much to set aside for the assessment — an estimate, not a return. If an accountant files your return with their own tax software, you give them the tax export (an RGS bridge statement), so they don't have to retype your figures.
The year you came to the Netherlands
If you moved to the Netherlands during a year, you were a resident taxpayer for part of it and a non-resident taxpayer for the rest. For that year you file not an ordinary return but an M-return, which keeps those two periods apart. The same applies to the year you leave.
That form was for years available on paper only. Since 2026 the M-return can be filed online in Mijn Belastingdienst from 1 May, with DigiD or with a recognised European login — which makes it considerably easier for anyone who did not yet have a DigiD when they arrived.
Updated October 2, 2026. General explanation of the Dutch rules, not tax advice — for your own situation, decide together with your accountant or the Dutch Tax Administration.