What your bookkeeping must legally contain, and how long you keep it
You keep your bookkeeping for seven years, and records about real estate for ten years. The bookkeeping includes at least the general ledger, the accounts receivable and payable records, the purchase and sales records, the stock records, and the payroll records if you have them. Added to that is everything needed to check what you declared: invoices, receipts, bank statements, contracts and your hours log. The period starts once a record is no longer current, and keeping it digitally is allowed, as long as it stays readable and verifiable.
This article walks through what must be in it, for how long, when the clock starts, what digital retention asks, what verifiable means and how you set it up as a maker without regretting it later. The tax explanation on this page follows Dutch law and is written for Dutch sole proprietorships (eenmanszaak).
This is general information, not tax or legal advice. basestep calculates and explains; you file yourself. If you are unsure about your situation, consult an adviser.
What must your bookkeeping contain at minimum?
Everything needed to check your tax returns. The Belastingdienst (the Dutch tax authority) explicitly names a number of parts as basic records:
- the general ledger, the summary of all your entries per account;
- the accounts receivable and payable records: who has to pay you, and whom you have to pay;
- the stock records, if you have stock;
- the purchase and sales records, so your purchase and your sales invoices;
- the payroll records, if you have staff.
For a sole proprietorship without staff and without stock, that comes down to: all invoices you send, all receipts and invoices you pay, your bank statements, your general ledger, and the documents that support your returns. Also think of your hours log if you want to meet the urencriterium (the 1,225-hour test), your mileage log if you drive for business, contracts and quotes, and the calendar or correspondence that explains a business expense.
The rule is not that you keep everything, but that you keep what lets the Belastingdienst check whether what you declared is correct. If you doubt whether something belongs, ask yourself: can I explain without this document why this amount is in my return? If not, it belongs.
- Basic records: general ledger, receivables and payables, purchases and sales, stock, payroll.
- For a sole proprietorship: invoices, receipts, statements, general ledger and the support for your returns.
- Also: hours, mileage, contracts, quotes and whatever explains an expense.
How long do you keep it?
Seven years. That is the statutory retention period for the basic records and for everything that supports your returns. It is in Article 52 of the Algemene wet inzake rijksbelastingen (AWR, the Dutch general act on state taxes). For records about real estate and rights to real estate, ten years applies, because the VAT (btw) on a building can be revised over a longer period. If you sell to consumers in other EU countries through the Unieregeling (the EU one stop shop for such sales) or the import scheme for web shops (invoerregeling), ten years applies to that as well.
For records other than the basic records, you can agree a shorter period with the Belastingdienst, and also the form in which you keep them. Without an agreement, seven years applies to everything that belongs to the bookkeeping. In practice the safest choice is: everything seven years, buildings ten, and throw nothing away unless you are sure the period is over.
Other laws can have longer periods, for example for personnel files or medical data; those fall outside this article. For a sole proprietorship with an AI project, seven and ten are the numbers that count.
- Seven years for the bookkeeping; Article 52 AWR.
- Ten years for real estate and for the Unieregeling.
- Shorter periods only by agreement with the Belastingdienst.
When does the period start to run?
When a record is no longer current. As long as something is still used in your bookkeeping, it belongs to it and the period does not run. Only when its current value lapses does the retention period start. The Belastingdienst gives the example of a contract: a four-year lease you keep for seven years after those four end, so eleven years in total.
For an invoice that means in practice: seven years after the end of the financial year it belongs to, because it was current in that year. So an invoice from March 2026 you keep until the end of 2033. For a business asset you depreciate, the period only runs from the moment it is fully depreciated or sold, because until then it comes back in your return every year.
The simple rule for those who do not want to calculate per document: throw away nothing younger than eight financial years, and track separately the end date of everything that lasts longer (contracts, business assets, buildings).
- The clock starts when the record is no longer current.
- An invoice: seven years after the financial year it belongs to.
- Something that lasts longer: seven years after it ends.
May it be digital, and what are the requirements then?
Yes. You may keep your bookkeeping digitally, and you may convert paper documents into a digital form. Three conditions come with that: the conversion is correct and complete, the data stay available for the whole period, and they can be made readable and verifiable within a reasonable time. The Belastingdienst is not concerned with the paper but with the information on it, and with the certainty that this information has not changed.
That puts three demands on how you keep things. The first is that you can find it again: a folder with five thousand files called scan.pdf is kept but not verifiable. The second is that it keeps existing: a backup you have restored once, and not only on the laptop you replace in four years. The third is that it stays readable: common file formats, and no software that will no longer exist in seven years to open it.
Whoever uses an accounting package or a bookkeeping platform usually has an export for that. The question you ask before choosing is: can I get my whole bookkeeping out in a form I can read without this package? The term XAF audit file on this site is about the standard form in which that is possible.
- Digital is allowed, also converted from paper, if it stays correct, complete and available.
- Findable, lasting (backup restored) and readable in common formats.
- Ask every package in advance: can everything come out.
What does verifiable mean?
It means that during an audit the Belastingdienst can check within a reasonable time whether your returns are correct, based on what you kept. That asks three things that have little to do with keeping as such. Every entry can be traced to a document: an invoice, a receipt, a statement. The documents have not been changed afterwards. And the whole adds up: what came into the bank is also in your turnover, and what you deducted as costs is on a receipt.
For invoices this means, among other things, that a sent invoice no longer changes. If it was wrong, you send a credit note and a new invoice; you do not edit the old one. That is not a formality but the core of verifiability: a series of consecutive, unchanged invoices is the proof that nothing was left out. The article on what an invoice must contain continues from there.
And it means your bookkeeping is up to date. A shoebox of receipts you only process in April is technically kept. But whoever has to explain in an audit why an expense from fourteen months ago was business stands weak. A quarter of an hour a week during the year itself is less work than a weekend in April.
- Every entry traceable to a document, and the documents unchanged.
- Sent invoices never change; wrong means a credit note and a new one.
- Up to date, because explaining afterwards is the weak point.
How do you set it up as a maker with an AI project?
Start at the source of your bookkeeping: your bank account and your invoices. A separate business account means every statement belongs to the bookkeeping in full, without searching for what was private. You send invoices from one system, with consecutive numbers, and that system keeps them; your email is not an archive. You photograph receipts on the day itself and attach them to the expense, with a word about what it was for.
Also think about what happens in your project itself. If your product receives payments, part of your bookkeeping is in your database: orders, payments, invoices to customers. Those records fall under the same seven-year retention obligation, even when a customer asks for deletion; you say so in your privacy statement. Keep them in a separate table or a separate export, so you can keep them while you clean up the rest. The article on the database describes that distinction.
And once a year, make a closed export of the whole year, in a common format, in a place outside the package and outside your laptop. That is your retention obligation in one action, regardless of which package you use in five years. The administration in basestep is built to do that: everything exportable, also when you leave.
- Separate account, invoices from one system, receipts on the day itself.
- Bookkeeping in your database: keep it for seven years, apart from what you clean up.
- Every year a closed export outside the package and outside your laptop.
Sources
Checked on 5 September 2026. The periods and the basic records come from the Belastingdienst; the legal basis is in the term bewaarplicht (the retention obligation) on this site.
Further reading
Three places that connect to this.
From first prompt to tax return.
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