What an invoice must legally contain

Which details are mandatory?

The Belastingdienst lists them on its page about invoice requirements:

• your full name and that of your customer, and the full address of both;
• your VAT identification number, and your KVK number if you are registered with KVK;
• the date on which the invoice was issued, and an invoice number;
• a description and the quantity of the goods delivered, or the nature and extent of the services;
• the date on which the delivery took place;
• the amount excluding VAT, the applicable VAT rate, and the VAT amount.

With several rates on one invoice, you split the amount excluding VAT per rate, with the VAT amount per rate. You also state any discounts you give, so that the amount on which VAT was calculated can be followed. And the invoice is in euros, or in another currency with the VAT amount in euros added.

Address means the real address where you work, not just a PO box. The VAT identification number is the number that starts with NL and ends with B and two digits. That is a different number from your omzetbelastingnummer, the VAT number you only use in contact with the Belastingdienst. The term factuurvereisten (invoice requirements) on this site gives the exact provision in the Dutch VAT Act (Wet op de omzetbelasting).

• Who: name and address of you and your client, your VAT identification number, your KVK number.
• When and which: invoice date, sequential number, delivery date.
• What and how much: description, quantity, amount excluding VAT, rate, VAT amount.

Why are they on it, and what goes wrong without them?

Because an invoice has two sides. For you it is the proof of your turnover and of the VAT you charged. For your client it is the proof with which they deduct the VAT they paid you as input VAT. An invoice that does not meet the requirements is not a valid invoice for that deduction, and the Belastingdienst can then refuse your client the deduction. That is why business clients sometimes ask for a new invoice when something is missing: it is about their money.

Every part has a function. The names and addresses say between whom the delivery took place. The VAT identification number says that you are a VAT-registered business that also pays this VAT over to the tax authority. The number and the date make the invoice unique and place it in a tax period. The delivery date determines which period the VAT belongs to if it differs from the invoice date. The description makes it possible to check whether the rate is right and whether it was a business expense. And the split into amount, rate and VAT shows the calculation.

Without those parts the invoice is not invalid as a claim (your client still has to pay), but it is invalid as a VAT document. For a maker who supplies businesses, that difference is the reason to set it up properly once.

• For you the proof of turnover, for your client the proof for the deduction.
• Every part makes something checkable: who, when, what, which rate.
• Incomplete does not make an invalid claim, but it does make an invalid VAT document.

How does numbering work, and why does an invoice never change again?

Invoice numbers are sequential and unique: every new invoice gets the next number in the series, without gaps and without duplicates. You may have several series, for example one per year, as long as each series continues. The purpose is that an auditor can see that nothing was left out: a gap in the series is a question, a duplicate number is a problem.

The second rule follows from that: an invoice you have sent does not change anymore. If it was wrong, you do not edit it. You send a credit note (creditfactuur) that reverses the old one, and then a new, correct invoice with a new number. That way the series stays complete and it stays visible what happened. An invoice you change afterwards is, for your client's bookkeeping, a different document from the one they received. That is exactly what makes checking impossible.

An invoicing program that locks a sent invoice and only allows a credit note enforces this. If you invoice from a word processor, you have to watch it yourself, and one day that goes wrong.

• Sequential and unique, without gaps; several series are allowed.
• Sent is final: a mistake becomes a credit note plus a new invoice.
• A system that locks invoices watches this for you.

When may you use a simplified invoice?

When the invoice amount is €100 or less, including VAT. Then you need to state fewer details; the Belastingdienst describes on its page about invoice requirements which details are then the minimum. In practice this means the receipt or the simple invoice for small amounts. It shows at least your details, the date, what was delivered, and the VAT amount or the details to calculate it.

For a maker who supplies services to businesses this rarely happens: most invoices are above €100, and a business client always wants a full invoice for their deduction anyway. If you supply small amounts to private individuals, for example a subscription of a few euros a month, the simplified invoice does matter. And then the first question is whether you have to issue an invoice at all: to private individuals it is in many cases not mandatory.

A simplified invoice also belongs in your bookkeeping, with a number, and the retention obligation applies to it as well.

• Up to and including €100 including VAT: fewer details are mandatory.
• Business clients still want a full invoice for their deduction.
• Simplified too: number it and keep it.

Which statements belong on it in special cases?

If you charge no VAT because the VAT is reverse-charged to your client, for example with a service to a business in another EU country, you state that on the invoice. Also add your client's VAT identification number: without that number you cannot apply the reverse charge. If you supply something that is exempt from VAT, you state that it is an exempt supply. And if you take part in the kleineondernemersregeling (KOR, the Dutch small businesses VAT scheme), there is no VAT on your invoice. It is then customary to state that you apply that scheme, so your client understands why.

For supplies to businesses in other EU countries, your customer's VAT identification number is also mandatory. You report those supplies in the opgaaf intracommunautaire prestaties, a periodic listing of your supplies to other EU countries. That is a separate topic, and the terms verlegde btw (reverse-charged VAT) and ICP-opgave on this site cover it.

The rule behind all these statements is the same: if something differs from the ordinary situation (Dutch client, Dutch VAT), the invoice says what differs and why. That makes it checkable for both sides.

• Reverse-charged: state it, with the VAT identification number of your client.
• Exempt: state that it is exempt.
• Small businesses scheme (KOR): no VAT, but do add the statement.

When must the invoice go out, and how do you keep it?

No later than the fifteenth day of the month after the month in which you delivered. If you deliver on 20 September, the invoice must be issued by 15 October at the latest. That is a statutory deadline from the Dutch VAT Act, and the term factuurvereisten gives the exact provision. In practice you invoice earlier: the sooner after the delivery, the faster you get paid, and the smaller the chance of a dispute about what was delivered.

You keep it for seven years, as part of your bookkeeping, together with the credit notes and the supporting documents. Digital is allowed, as long as the invoice stays readable and unchanged; a PDF that your system fixed when it was sent meets that requirement. If you invoice through an invoicing program, you have that archive automatically. If you do it by email, you keep the sent files separately, because a mailbox is not bookkeeping.

And send the invoice in a form your client can process. For more and more business clients, that means an e-invoice in a structured format next to the PDF, which their accounting software reads in directly. The term e-factuur (e-invoice) explains what that is and when it becomes mandatory.

• No later than the fifteenth of the month after delivery; earlier is better.
• Keep for seven years, readable and unchanged; a mailbox is not an archive.
• PDF, and where the client can handle it: an e-invoice.

Sources

Checked on 5 September 2026. The list comes literally from the Belastingdienst; the statutory provisions are in the term factuurvereisten on this site.

• Belastingdienst, invoice requirements
• Belastingdienst, mandatory details on your invoice

Further reading

Three places that connect to this.