Mandatory invoice details in Belgium: the checklist to run through

One missing detail on an invoice, and the accountant on the other side bounces it. Worst case, a VAT deduction refused months later at an audit. Nothing complicated about it, but forgetting a single line can turn a routine document into a headache. Here's what to check in a few seconds.

What every invoice must show

The core details are the same across Europe — Belgium applies the VAT Directive rules. A full invoice should carry:

• the date of issue;
• a unique sequential invoice number;
• your name or company name, your address and your VAT number;
• the name, address and VAT number of your customer (when they are liable for the tax);
• the description and quantity of the goods or services supplied;
• the unit price excluding VAT, plus any discounts or rebates;
• the date of the transaction if it differs from the invoice date;
• the taxable amount per rate;
• the VAT rate applied and the VAT amount due;
• the breakdown of VAT by rate or, where relevant, the reference to the exemption.

The mentions that depend on the case

Beyond the basics, some situations call for a specific mention:

• Reverse charge: when the VAT is owed by the customer rather than you — typically construction works between taxable persons — the invoice carries no VAT but the mention 'Reverse charge'.
• Exemption scheme: if you invoice without VAT under the small-business exemption scheme, the invoice must carry a mention referring to that scheme. For the exact wording, rely on the Belgian tax authority.
• Self-billing: when the customer draws up the invoice in your name, it carries the mention 'Self-billing'.

By when you have to issue it

The rule is precise in Belgium: the invoice must be issued by the 15th day of the month following the one in which the transaction took place. So don't let an end-of-month delivery sit around.

Getting it right without thinking about it every time

Checking this list by hand on every invoice is doable, but it's exactly the kind of task a tool does better than we do. In Voilo, invoices are generated in a compliant format: your details and VAT number are already in place, numbering stays sequential, and the CBE/KBO lookup pulls your customer's name, address and company number from their number — fewer typos on data that has to be exact. When the invoice goes out in structured format, those fields already travel in the right place, as our Peppol guide explains.

What's included by plan is set out on the pricing page. And for the special cases — exemptions, intra-EU transactions, specific sectors — the Belgian tax authority remains the up-to-date official source.