Correcting an error in a previous financial year: VAT, profit and the assessment

Written by Ilias Aarrass6 min read · Published on 18 September 2026 · Last reviewed on 18 September 2026

In short

A VAT error is fixed with a correction return, an error in your profit return with an amended return, and a balance sheet error in the oldest year whose assessment is not yet final.

If the VAT correction stays under € 1,000, you may include it in your next return.
If a final assessment exists, you request an ex officio reduction within five years.
Forgotten depreciation is not caught up at once: you correct the book value in the oldest open year.
A forgotten invoice is sent now and declared in the period in which you send it.

When closing your year, or clearing out an old folder, you sometimes find that the previous year was wrong. An invoice never sent, a private expense booked as a cost, an asset depreciated too quickly. That is annoying, but almost always fixable. Which route you take depends on three things: is it VAT or profit, is the assessment already final, and does the error sit in your balance sheet or your profit and loss account. This article covers all three.

A VAT error: the correction return

If your VAT return was wrong, you fix it with a correction return. You are obliged to do so as soon as you spot the error, and you do it as quickly as possible: the sooner, the less tax interest and the smaller the chance it is treated as culpable. If the net amount to pay or reclaim is less than € 1,000, you may simply include the correction in your next return. See filing a VAT correction.

Note the difference between an error and an invoice you still have to send. An invoice you forgot to send you simply send now with today's date and declare in the period in which you send it. An invoice you did send but entered wrongly in your return you correct with a correction return for that old period.

An error in your profit return

If you have filed your income tax return but not yet received a final assessment, you simply file an amended return. That can be done digitally and needs no covering note. If a final assessment has been issued, it depends on the deadline: within six weeks of the date you object, after that you request an ex officio reduction. The latter is possible up to five years after the end of the tax year. See objecting to an assessment.

If the error was to your disadvantage, you get money back or your assessment is reduced. If it was in your favour, an additional assessment with tax interest follows. The tax authorities may go back five years, and twelve years for foreign income. See additional assessments.

Balance sheet errors: the oldest year still open

Some errors do not sit in one year but carry through your balance sheet. Think of an asset depreciated too fast or too slowly, stock valued too high or a private withdrawal booked as a cost. You do not fix those by redoing all the old years, but in the oldest year whose assessment is not yet final. That is what is known as the error doctrine.

In practice: you correct the balance sheet item in the first open year and settle the difference there. So you cannot simply take forgotten depreciation in one go in any year you like. If you are unsure whether an error sits in your balance sheet or in your costs, look at the effect: does only this year change, or does something carry into later years? See reading a balance sheet and profit and loss account.

Worked example: a van depreciated too fast

Purchase price of the van: € 20,000
Depreciated over 3 years instead of 5: € 6,667 a year
Book value in your records after 3 years: € 0
Book value it should have been: € 8,000

Result: You correct the book value in the oldest year still open: the van returns to your balance sheet there at € 8,000 and that amount counts as profit that year. From then on you depreciate over the remaining years.

Preventing it from happening again

Most errors in old years arise because the bookkeeping is left too long. A fixed monthly routine of half an hour prevents almost all of these corrections: send invoices, scan receipts, update the bank, check outstanding items. See bookkeeping: the monthly routine. If you already have a backlog, start with the year the first question is about and work from there, see clearing a bookkeeping backlog.

At year-end, check four things as standard: do your VAT returns reconcile with your revenue, does your bank balance match your records, are your outstanding invoices still listed and is your stock right. Those four reconciliations catch nine out of ten errors before they become a problem. See the year-end checklist.

Frequently asked questions

How far back can I correct an error?

For VAT you correct the relevant period with a correction return. For income tax you can request an ex officio reduction up to five years after the end of the tax year.

Must I report an error or may I wait?

For VAT you are obliged to correct as soon as you know. Waiting costs you tax interest and increases the chance it is treated as culpable.

I forgot to send an invoice. Is that an error in that year?

Not for VAT: you send it now and declare it in the period of sending. For your profit the revenue belongs to the year in which you did the work, so you correct that part in that year.

What if I underdepreciated for years?

You do not catch that up in one go. You correct the book value in the oldest year not yet final, and from then on depreciate over the remaining useful life.

Sources

Correcting a VAT return: the € 1,000 limitBelastingdienst · belastingdienst.nl
Business costs and determining profitBelastingdienst · belastingdienst.nl

Sources checked on 18 September 2026

This article provides general information based on the rules known for 2026 and does not replace personal tax advice. For your specific situation, we're happy to take a look with you.