Why must an invoice be compliant?
In Belgium, an invoice is not just a payment document — it is a mandatory tax document. An incomplete or incorrect invoice can result in:
- A refusal to pay from the customer
- A rejection of VAT deduction during a tax audit
- Fines of up to 10,000 euros
- Disputes in case of non-payment (invoice not enforceable)
The complete checklist — mandatory mentions
Information about you (the seller)
- Name / business name
- Complete address
- Business number (BE XXXX.XXX.XXX)
- VAT number (BE + business number) — if liable
- Bank details (IBAN + BIC) — recommended but not mandatory
Information about your customer (the buyer)
- Name / business name
- Complete address
- Customer's VAT number (for B2B invoices)
Information about the invoice itself
- Invoice number unique and sequential (mandatory — e.g.: FACT-2024-0042)
- Invoice issue date
- Service date or delivery date (if different)
Description of services
- Clear description of each service or product
- Quantity
- Unit price excluding VAT
- Applicable VAT rate (6%, 12%, 21% or 0%)
- VAT amount per line and total
- Total excluding VAT
- Total VAT
- Total including VAT (TTC)
Payment terms
- Payment deadline — in Belgium, the legal B2B deadline is 30 days unless otherwise agreed
- Late interest rate (legal rate or agreed rate)
- Fixed compensation clause (minimum 40 euros for commercial claims)
Specific mentions depending on VAT regime
If you are under VAT exemption
You must add:
"VAT exemption regime — Vrijstellingsregeling van de belasting"
And you do not indicate any VAT rate or amount.
If you apply the co-contractor regime (article 20)
"VAT due by co-contractor — art. 20 A.R. n°1"
If you invoice with reverse charge (foreign EU customer)
"Reverse charge / Autoliquidation — Article 196 Directive 2006/112/CE"
The 5 most common errors
- Non-sequential numbering — a single sequence, without gaps, without duplicates
- Customer VAT number missing on B2B invoices — blocks customer's VAT deduction
- Service date forgotten when it differs from the invoice date
- VAT exemption mention absent for liable persons under exemption
- IBAN missing — not legally mandatory but a source of payment delays
Ledgerly takes care of everything
Each invoice created with Ledgerly automatically complies with all these obligations: sequential numbering, legal mentions according to your VAT regime, Belgian VAT rates, bank details. You don't have to remember this checklist.
Try for free — your first invoices will be compliant in minutes.
```