How do you write an invoice? These are the most important parts

A correct invoice is legally required and financially crucial — without a correct invoice, there is no VAT deduction for the customer, possibly no payment, and a risk of fines from the Tax and Customs Administration. Requirements in Art. 35a of the VAT Act: name and address of both parties, VAT numbers, invoice number, date, delivery, amount, and VAT. For SME BVs: standard template in accounting software. Below are mandatory components, smart additions, and pitfalls.

The short answer

• Legal requirements: Art. 35a VAT Act — Name and address, VAT numbers, number, date, supply, amount.
• Sequence number: sequential, no gaps.
• Payment term: typically 14-30 days.
• Accounting software: Moneybird, Yuki, and Exact offer compliant templates.
• Retention period:7 years (10 for real estate).

Mandatory components

1. Name and address: both provider and recipient.
2. VAT number: both parties (NL000000000B01 format).
3. Chamber of Commerce number: of the issuer.
4. Invoice number: sequential, unique.
5. Invoice date: day of issue.
6. Date of delivery: if different from invoice date.
7. Description: what has been delivered (product/service).
8. Quantity and unit price: for goods.
9. Amount excl. VAT.
10. VAT rate and amount: specify per rate (21%, 9%, 0%).
11. Total incl. VAT.

Additional information

Not legally required but smart:

• Payment term: e.g. “within 14 days of invoice date”.
• Bank details: IBAN and BIC.
• Payment reference: invoice number as description.
• Reference to terms and conditions: “our general terms and conditions, filed with…”, apply to this invoice.
• Discount scheme:e.g. “2% discount for payment within 7 days”.
• Penalty for non-payment: interest rate for exceeding the deadline.

Specific cases

VAT-exempt or 0%

State on invoice:

• “VAT exempt pursuant to Art. X VAT Act” (e.g. education, healthcare).
• “Intra-Community supply — VAT 0%” (EU export).
• “VAT reversed” (subcontractors in construction, VAT reverse charge scheme).

Anglo-Saxon factoring

For factoring: mention of factor name on invoice (open factoring):

Payment can only be made to [Factor Name], IBAN …”

By prepayment

For advance invoice (prepayment): state “advance for [description]” and offset against the paid advance on the final invoice.

Serial numbers

Sequential, without gaps. Practical systems:

• 2024-001, 2024-002 (reset annually).
• 10000, 10001 (continuing over the years).
• F-2024-001 (with prefix per month group).

No gaps — for credit note: separate number series or in sequential number.

Common mistakes

• VAT number incorrect or missing.
• No VAT specification per rate.
• Delivery date is missing if invoice date differs.
• Adding amounts incorrect.
• Gaps in invoice numbers.
• No IBAN or payment term.
• Unclear description of performance.

Digital invoicing

PDF invoices via email are common. Since 2026 (expected): UBL format mandatory for B2G in the EU. Accounting software generates UBL export.

Electronic archiving: Retain for 7 years in a searchable format. The accounting package handles this automatically.

Honest recommendation

For SME BVs: use accounting software (Moneybird, Yuki, Exact, Twinfield) — automatically compliant templates. For small freelancers: the standard Chamber of Commerce template suffices. Plus clear payment terms (14-30 days) and bank details. For international transactions: VAT specification according to 0% rules and reference to terms and conditions. Periodic check on invoice sequence numbering and VAT return reconciliation.

For other topics: VAT return, payment reminder and engaging a collection agency.

Frequently Asked Questions