What Must Be on an Invoice? (Freelancer Checklist 2026)

An invoice that misses required details can be rejected by your client, and may also create issues in a tax audit. Yet many freelancers still forget one or more mandatory elements, often because they are unclear on Dutch invoice rules.

This guide gives you the complete list of required invoice details in the Netherlands, with examples and a practical checklist you can use before sending any invoice.

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The 10 mandatory invoice details for freelancers

These are the elements the Dutch Tax Authority (Belastingdienst) requires on every invoice.

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1. Your full business name and address

Use the business name under which you are registered at the KvK. If you work under your own name, include your first and last name.

Also include your full business address: street, house number, postal code, and city.

Example:

Freelance Studio / or: John de Vries
Example Street 12
1234 AB Amsterdam

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2. KvK number

If you are registered as an entrepreneur, your KvK number must appear on every invoice.

A KvK number contains 8 digits, for example: KvK: 12345678

Not registered yet? Then you are generally not allowed to issue VAT invoices.

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3. VAT identification number

Your VAT identification number must be included on all invoices and client-facing documents. Format:

NL123456789B01

As a Dutch sole proprietor, you have two VAT numbers:

Always use the VAT identification number on invoices.

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4. Client name and address

Include your client's full name or company name and billing address. For larger companies, add a department or contact person if needed.

Example:

Example B.V.
Attn: Finance Department
Client Street 5
5678 CD Rotterdam

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5. Client VAT number (for EU business clients)

If you invoice a business in another EU country, the client's VAT number is mandatory for reverse charge and ICP reporting.

For Dutch clients, this is usually optional but common on B2B invoices.

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6. Unique, sequential invoice number

Each invoice must have a unique number. Numbering should be sequential and consistent.

Accepted formats include:

Tip: Do not restart at 001 per client, otherwise you create duplicates in your accounting.

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7. Invoice date

Always include the date the invoice is issued. This date also starts the payment term.

By law, invoices must be sent no later than the 15th day of the month after delivery.

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8. Description of delivered services or products

Avoid vague text such as "Work in April." A proper description should include:

• What you delivered
• Which period it covers
• Number of hours or units (if relevant)
• Hourly rate or unit price

Too vague:

Work performed May 2026

Correct:

E-commerce webshop development — phase 2 (backend integration), 24 hours at EUR 110.00

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9. Amounts: excluding VAT, VAT amount, and total including VAT

A single final amount is not enough. You must show all three:

If you use multiple VAT rates on one invoice (for example 9% and 21%), split subtotals and VAT amounts per rate.

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10. IBAN and payment term

Include your IBAN so clients know where to pay. Also include a payment term or due date.

Recommended wording:

Please transfer EUR 919.60 before 15 March 2026 to IBAN NL00 BANK 0000 0000 00, in the name of Freelance Studio, referencing invoice number 2026-001.

A fixed due date usually works better than "within 30 days."

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Optional but useful additions

In addition to legal requirements, these elements improve professionalism and speed up payments:

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Exceptions and special cases

Simplified invoice (up to EUR 100)

If the total amount including VAT is up to EUR 100, you may issue a simplified invoice with fewer required details.

KOR (no VAT charged)

If you are under the KOR scheme (turnover below EUR 20,000), include:

VAT exempt under Article 25 Dutch VAT Act (KOR)

Do not include a VAT rate or VAT amount.

Reverse charge (EU business clients)

When invoicing VAT-registered businesses in other EU countries:

VAT reverse charged / BTW verlegd

Also include the client's VAT number.

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What if your invoice is incomplete?

Two common consequences:

• Client rejection: the invoice is returned and payment is delayed.
• Tax risk: the Belastingdienst may treat the invoice as invalid during an audit.

If needed, send a corrected version with the same number plus a revision marker, such as 2026-001-R.

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Freelancer invoice checklist

Use this before sending any invoice:

MANDATORY INVOICE DETAILS — FREELANCER CHECKLIST

Your details
☐ Business name or personal name
☐ Business address (street, postal code, city)
☐ KvK number
☐ VAT identification number (NL...B01)

Client details
☐ Client name or company name
☐ Client billing address
☐ Client VAT number (mandatory for EU business clients)

Invoice details
☐ Unique, sequential invoice number
☐ Invoice date
☐ Clear description of service or product

Amounts
☐ Subtotal excluding VAT
☐ VAT rate (0%, 9%, or 21%) and VAT amount shown separately
☐ Total including VAT

Payment
☐ IBAN bank account number
☐ Payment term or specific due date

Exceptions (if relevant)
☐ KOR exemption line if VAT-exempt
☐ "VAT reverse charged" and client VAT number for EU clients

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Frequently Asked Questions

Is my KvK number mandatory on every invoice?

Yes. If you are registered with the KvK, you must include your KvK number on all invoices.

Do I need to include my client's VAT number?

Yes for VAT-registered businesses in other EU countries. For Dutch clients, it is usually optional but common.

Can I issue an invoice in English?

Yes. Dutch law focuses on required content, not the language.

What if I use the KOR scheme?

Include the KOR exemption line and do not show VAT amounts.

What happens if my invoice is incomplete?

Your client can reject it and the Belastingdienst can challenge it. Send a corrected invoice if needed.

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Next step: read How to Invoice as a Freelancer in the Netherlands or Unpaid Invoice — What to Do.