In Belgium, every invoice issued by a VAT-registered business must comply with precise rules set out in the VAT Code and Royal Decree No. 1. A non-compliant invoice can be rejected by the tax authorities, meaning your client cannot deduct the VAT and you risk penalties. This tutorial explains every mandatory detail in depth and guides you through creating your first compliant invoice in just a few minutes.

When must you issue an invoice?

Knowing when the obligation applies is the first step towards producing a compliant invoice every time.

The invoicing obligation

In Belgium, you must issue an invoice in the following situations:

  • Supply of goods or services to another VAT-registered business (B2B)
  • Supply of goods or services to a non-taxable legal person (e.g. a non-VAT-registered non-profit)
  • Distance sales (e-commerce) above certain thresholds
  • Intra-Community supplies of goods
  • Advance payments received before delivery or performance

Exceptions to the invoicing obligation

You are not required to issue an invoice for:

  • Sales to private individuals (B2C), unless the customer requests one or the law requires it for your sector (construction, garages, etc.)
  • Transactions exempt from VAT under Article 44 of the VAT Code (education, medical care, etc.)

Issuance deadline

The invoice must be issued by no later than the 15th day of the month following the delivery of goods or completion of the service. For example, for a service performed on 10 March 2026, the invoice must be issued by 15 April 2026 at the latest.

The mandatory details on a compliant invoice in Belgium

The VAT Code (Article 5 of Royal Decree No. 1) requires the following details on every invoice:

1. The word "Invoice" (or "Factuur" / "Rechnung")

The word "Invoice" must appear clearly at the top of the document. In Belgium, it is common to use the bilingual wording "Facture / Factuur" for businesses active in both language communities.

2. A unique sequential number

Every invoice must carry a unique, sequential number. The numbering must be continuous, with no gaps or duplicates. Common format examples:

  • 2026-001, 2026-002, 2026-003…
  • F2026/0001, F2026/0002…
  • 20260001, 20260002…

Tip: Use a prefix with the year to make filing easier. Never restart your numbering partway through the year.

3. Issue date

The date on which the invoice is issued. This date determines the VAT return period in which the transaction must be declared.

4. Full details of the supplier (issuer)

You must state:

  • Name or company name (as registered with the CBE)
  • Full address of the registered office (street, number, postcode, municipality)
  • Company number (CBE number, format 0XXX.XXX.XXX)
  • VAT number (format BE 0XXX.XXX.XXX)

5. Full details of the customer (recipient)

You must state:

  • The customer's name or company name
  • The customer's full address
  • The customer's VAT number (if the customer is VAT-registered)

6. Date of delivery or performance

The date on which the goods were delivered or the service was completed. If this date coincides with the invoice's issue date, a single mention is enough (e.g. "Invoice and performance date: 15/03/2026").

7. A detailed description of the goods or services

A description precise enough to identify the nature of the delivery or service. For example:

Good description:

  • "Development of an e-commerce website – 40 hours of work"
  • "Supply of 500 kg of T55 wheat flour"
  • "Digital marketing consultancy – assignment from 01/03 to 15/03/2026"

Poor description (too vague):

  • "Provision of services"
  • "Miscellaneous"
  • "Work"

8. Quantity and unit price

For each invoice line:

  • The quantity delivered or number of hours worked
  • The unit price, excluding VAT

9. Taxable amount (amount excluding VAT)

The total amount excluding VAT for each line and for the invoice as a whole.

10. VAT rate applied

The VAT rate applicable to each line (21%, 12%, 6% or 0%). If different rates apply, each rate must be listed separately with the corresponding taxable amount.

11. VAT amount

The VAT amount calculated for each applicable rate, and the total VAT amount.

12. Total amount including VAT

The total amount payable, including all taxes.

13. Any discounts

If you grant a cash discount or a rebate, state it clearly on the invoice, along with the discount amount.

14. Special mentions (where applicable)

Certain situations require additional wording:

Situation Mandatory wording
Reverse charge (co-contractor) "Reverse charge – Article 20 of Royal Decree No. 1" or "VAT payable by the co-contractor"
Exemption scheme "Small business subject to the tax exemption scheme – VAT not applicable"
Margin scheme "Margin scheme – second-hand goods"
Intra-Community supply "VAT exemption – Article 39a of the VAT Code"
Export outside the EU "VAT exemption – Article 39 of the VAT Code"
Advance payment invoice "Advance payment invoice" or "Invoice relating to an advance payment"

15. Payment terms

Although not strictly required by the VAT Code, it is strongly recommended to state:

  • The payment term (e.g. 30 days from invoice date)
  • The bank account number (IBAN) for payment
  • The structured or free-form payment reference for the transfer
  • The applicable late payment penalties (law of 2 August 2002 on combating late payment in commercial transactions)

Visual summary: structure of a compliant invoice in Belgium

Here is the recommended structure for your invoice:

+----------------------------------------------------------+
|  [YOUR LOGO]                                              |
|                                                            |
|  INVOICE                                                   |
|                                                            |
|  Number: F2026/0001                                        |
|  Date: 15/03/2026                                          |
|  Service date: 01/03/2026 - 15/03/2026                     |
|                                                            |
|  SUPPLIER:                     CUSTOMER:                   |
|  Your Company SRL              Client SA                   |
|  Rue de la Loi 42              Avenue Louise 100            |
|  1000 Brussels                 1050 Ixelles                 |
|  VAT: BE 0123.456.789          VAT: BE 0987.654.321         |
|                                                            |
|  +---------+---------------------------+-----+--------+    |
|  | Qty     | Description               | Unit| Total  |    |
|  +---------+---------------------------+-----+--------+    |
|  | 40 h    | Website development       | 75  | 3000.00|    |
|  | 1       | Annual hosting            | 150 |  150.00|    |
|  +---------+---------------------------+-----+--------+    |
|                                                            |
|  Subtotal excl. VAT:                            3,150.00   |
|  VAT 21%:                                          661.50   |
|  ----------------------------------------------------------|
|  TOTAL incl. VAT:                                3,811.50   |
|                                                            |
|  Payment: 30 days from invoice date                        |
|  IBAN: BE68 5390 0754 7034                                  |
|  Reference: F2026/0001                                      |
|                                                            |
|  In the event of late payment, interest of 8% per year     |
|  will apply automatically, without formal notice.          |
+----------------------------------------------------------+

Step-by-step tutorial: create your compliant invoice

Using invoicing software is the most reliable way to create compliant invoices. These tools automatically handle numbering, VAT calculations and mandatory details.

Popular invoicing software in Belgium:

Software Price Strengths
Billit From EUR 15/month Belgian, integrates with Belgian banks, Peppol-compliant
Teamleader From EUR 37.50/month CRM + invoicing + project management, Belgian
Yuki Quote on request Automatic digitisation, integrated accounting
Horus Quote on request Full accounting software with an invoicing module
Exact Online From EUR 29/month Cloud-based, popular with accountants
Facturis Free (basic version) Simple, for start-ups
CashDesk From EUR 12/month Specialised in retail, till receipts

Steps with invoicing software (generic example):

  1. Create your account: sign up and configure your company details (name, address, VAT number, logo, bank details)
  2. Configure your VAT settings: select the VAT rates you use (21%, 6%, etc.)
  3. Add a customer: enter the customer's details (name, address, VAT number)
  4. Create a new invoice: click "New invoice"
  5. Add invoice lines: description, quantity, unit price, VAT rate
  6. Check the result: the software automatically calculates VAT and the total including VAT
  7. Send the invoice: by email (PDF) or via Peppol for e-invoicing

Method 2: Using Excel or Google Sheets

For beginners with a low volume of invoices, a spreadsheet can work. However, this method is riskier (calculation errors, missed mandatory details), makes a compliant invoice harder to guarantee, and is not suitable for e-invoicing.

Steps:

  1. Create a template with all the mandatory details listed above
  2. Use formulas to automatically calculate:
    • The subtotal per line: =quantity * unit_price
    • The subtotal excluding VAT: =SUM(line_totals)
    • VAT: =subtotal * VAT_rate
    • The total including VAT: =subtotal + VAT
  3. Number each invoice manually (watch for continuity)
  4. Export to PDF to send to the customer
  5. Archive both the original file and the PDF

Warning: This method is not recommended for high volumes. Switch to invoicing software quickly to avoid errors.

Method 3: Using Word or Google Docs

Even more basic, this method involves creating an invoice template in a word processor. Calculations must be done manually or with a calculator. This is the least reliable and least recommended method.

E-invoicing in Belgium (Peppol)

E-invoicing has become a major topic in Belgium:

  • Since 2024: e-invoicing has been mandatory for public procurement (B2G) via the Peppol network
  • From 2026: the obligation to e-invoice between businesses (B2B) is being introduced progressively
  • The standard format is Peppol BIS Billing 3.0 (based on the UBL format)

What is Peppol?

Peppol (Pan-European Public Procurement OnLine) is an international network that enables the exchange of electronic commercial documents (invoices, purchase orders, etc.) between businesses. Each participant is identified by a Peppol ID, usually based on their Belgian VAT number.

How do you send invoices via Peppol?

  1. Choose a Peppol access point: most Belgian invoicing software already integrates Peppol (Billit, Teamleader, Exact Online, etc.)
  2. Register your Peppol ID: this is usually automatic when you configure the software
  3. Create your invoice in the software
  4. Send via Peppol: the software converts the invoice to UBL format and sends it to the recipient over the Peppol network

Credit notes

If you need to correct an invoice that has already been issued (a price error, returned goods, a discount granted after the fact), you must issue a credit note (rather than simply editing or deleting the original invoice).

Mandatory details on a credit note

The credit note must contain:

  • The wording "Credit note" (or "Creditnota")
  • A unique sequential number (can be in a separate series, e.g. CN2026/0001)
  • A reference to the original invoice (number and date)
  • The reason for the correction
  • The corrected amounts (including VAT)

Credit note example

CREDIT NOTE CN2026/0001
Date: 20/03/2026
Reference: Invoice F2026/0001 of 15/03/2026
Reason: Price error on the hosting service

Annual hosting: -EUR 50.00 excl. VAT
VAT 21%: -EUR 10.50
Total: -EUR 60.50 incl. VAT

Payment terms and late payment penalties

Payment terms between businesses (B2B)

The Belgian law of 2 August 2002 (as amended) sets the following rules for transactions between businesses:

  • Maximum payment term: 60 days from receipt of the invoice (unless a reasonable agreement states otherwise)
  • Verification period: a maximum of 30 days to check the conformity of the goods or services

Late payment interest

In the event of late payment, interest is automatically due, with no formal notice required:

  • The interest rate is set every six months by FPS Finance (published in the Belgian Official Gazette)
  • In 2026, the reference rate is around 8% per year for commercial transactions
  • A fixed recovery compensation of EUR 40 is also automatically due

Payment terms with public authorities (B2G)

For public contracts, the payment term is 30 days from receipt of the invoice.

Invoice retention

Keeping every compliant invoice on file for the required period is a legal obligation, not just good practice.

Retention period

In Belgium, invoices (issued and received) must be kept for:

  • 7 years for VAT purposes (from 1 January of the year following the invoice date)
  • 10 years under commercial law (Companies and Associations Code)

Retention format

  • Paper invoices can be kept in paper form or digitised (scanned)
  • Electronic invoices must be kept in their original electronic format
  • Readability, content integrity and authenticity of origin must be guaranteed throughout the retention period

Common mistakes to avoid

  1. Forgetting the customer's VAT number: without a VAT number, your customer cannot deduct the VAT on your invoice
  2. Too vague a description: "miscellaneous" or "service" are not acceptable descriptions
  3. VAT rate error: always check you are applying the correct rate (21% for most services)
  4. Non-sequential numbering: a "gap" in the numbering (e.g. jumping from F001 to F003) attracts attention during a tax audit
  5. Forgetting the special wording: for reverse charge, the exemption scheme, etc., the special wording is mandatory
  6. Invoice missing the service date: the service date is a mandatory detail, separate from the invoice date
  7. Not keeping invoices: premature destruction of invoices can cause problems during a tax audit

Useful resources

Conclusion

Creating a compliant invoice in Belgium isn't complicated, but it does require rigour. Between 12 and 15 mandatory details must appear on every invoice, and even a small omission can cause problems during a tax audit. Using invoicing software is strongly recommended: it automates numbering, VAT calculations and mandatory details, reducing the risk of error to almost zero.

With the progressive rollout of e-invoicing via Peppol, it's more important than ever to equip yourself with the right tool. Most Belgian invoicing software already includes this feature, letting you stay compliant with no extra effort.

This article was written by the Espero-Soft team for the blog dedicated to entrepreneurs in Belgium. For personalised advice on invoicing, consult your accountant.