Creating your first invoice: what must be on it?
Written by Ilias Aarrass7 min read · Published on · Last reviewed on 
In short
Your invoice needs a unique consecutive number, the invoice and delivery date, your name, address, KVK number and VAT ID, the client's details, a description and the amounts with the VAT rate.
- You send the invoice by the 15th day of the month following the month of delivery.
- Invoice numbers must be consecutive and each number may occur only once, with no gaps in the series.
- With a reverse charge you state 'VAT reverse-charged' plus your client's VAT number; under the small business scheme you invoice without a VAT amount or rate.
- Keep sent invoices for seven years in the format you sent them; digital is fully valid.
Your first assignment is in and now you need to send an invoice. An invoice is more than an amount and a bank account number: the tax authorities have requirements for what it must contain. An incomplete invoice can cause problems with your VAT. This article explains exactly which details are mandatory.
Which details are mandatory on an invoice?
Every invoice must show your business name and address, your VAT identification number and your KvK number. You also state the name and address of your client, a unique invoice number, the invoice date and the date of delivery. In addition you put a description of what you delivered, the amount excluding VAT, the VAT rate and amount, and the total amount.
Why is a unique invoice number important?
Invoice numbers must be sequential and unique. So you may not skip numbers or use them twice. The tax authorities use this to check whether your records are complete. A logical structure, for example by year and sequence number, keeps it clear.
When do you not charge VAT?
In some cases you don't charge VAT, for example under the reverse-charge scheme or with clients abroad. Then you put no VAT on the invoice, but state why: for example 'VAT reverse-charged' with your client's VAT number. If you fall under the KOR small business scheme, you also invoice without VAT.
How do you keep your invoices?
You're obliged to keep your invoices for seven years, both the invoices you send and those you receive. A digital copy is allowed. Preferably use bookkeeping software that numbers and stores your invoices automatically; that prevents mistakes and saves time at your VAT return.
The mandatory elements as a checklist
The law prescribes exactly what an invoice must contain. If something is missing, your client cannot deduct the VAT and you run into trouble in an audit. This is the complete list.
- A unique, consecutive invoice number, without gaps.
- The invoice date, and the delivery date if different.
- Your name, address, Chamber of Commerce number and VAT ID.
- Your client's name and address.
- A clear description of what you supplied, with quantity or scope.
- The amount excluding VAT, the VAT rate, the VAT amount and the total.
- With a reverse charge: the words 'VAT reverse-charged' plus your client's VAT number; under the small business scheme: no VAT and no rate.
- Practical, not mandatory: payment term, IBAN and a reference to your terms.
Frequently asked questions
What must my invoice contain?
A consecutive number, invoice date, your details with Chamber of Commerce number and VAT ID, the client's details, a description, and the amounts with VAT rate and VAT amount. With a reverse charge, add 'VAT reverse-charged' plus the client's VAT number.
May I choose my own invoice numbers?
The format yes, the sequence no: numbers must be consecutive and complete, without gaps. A deleted draft may not leave a hole in the series.
Within what period must I invoice?
By the 15th of the month following delivery. Practically: invoice on delivery; that also starts your payment term.
How do I invoice under the small business scheme?
Without a VAT amount and without a rate. State that you are exempt under the small business scheme, so your client knows why no VAT appears.
Must an invoice be on paper or is digital fine?
Digital is fully equivalent; a PDF by email is the norm. Keep every sent invoice for seven years, in the format you sent it.
What if I find an error on the invoice?
You never edit a sent invoice; you correct with a credit invoice and send a new, correct one. See credit invoice.
Sources
- Invoice requirements: which details are mandatoryBelastingdienst · belastingdienst.nl
- Keeping records: seven yearsBelastingdienst · belastingdienst.nl
Sources checked on
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.
