Pro forma invoices: what they are for in Belgium

Published on 13/07/2026 · By Antoine Lemmens, Eazyclick. Each rule links to its official source.

A customer asks for a “pro forma” before ordering, or your bank requires one for financing. This document looks like an invoice but is not one. Here is what it is used for in Belgium, what it should contain and what happens when a customer pays against it.

What is a pro forma invoice?

A pro forma invoice is a document showing, before the sale, what the invoice will contain: products or services, prices, VAT, payment and delivery terms. It provides information or secures approval of an offer. Despite its name, it is not an invoice: it does not make VAT payable.

For your customer, the consequence is simple: deducting VAT requires a valid invoice (specific FAQ on efacture.belgium.be, question 24), and a pro forma does not count as one.

What is a pro forma invoice used for?

It communicates a firm price before the sale, in a format close to the final invoice. It is mainly used to secure internal order approval at the customer's business, request payment before delivery, or support a funding or grant application requiring a detailed price before purchase.

• Purchase approval: your customer's purchasing department commits the expenditure based on the pro forma.
• Advance payment: the customer pays before delivery; the actual invoice follows receipt of payment (see below).
• Funding application: a bank, leasing provider or grant body requests a detailed price.

Is a pro forma invoice mandatory?

No. No VAT rule requires you to issue a pro forma: it is an optional commercial document you prepare if your customer asks for it. What is mandatory is an invoice, issued within the deadlines and, between Belgian VAT-registered businesses, as a structured electronic invoice sent through Peppol. A pro forma never replaces this invoice.

Invoicing obligations are listed by the FPS Finance; the Peppol obligation is explained in the complete Peppol guide for Belgium.

Pro forma, quote or deposit invoice: what's the difference?

A quote is an offer detailing a price for the customer to accept; a pro forma presents the same information in the format of the future invoice; a deposit invoice is a real invoice, issued when a partial payment is received. Only the deposit invoice carries VAT to declare and, between businesses, goes through Peppol.

• Quote: a price offer, often signed by the customer; no VAT due.
• Pro forma: a preview of the future invoice; no VAT due and no right to deduct it.
• Deposit invoice: a real invoice for a partial payment; VAT becomes due on receipt of payment.

What information should a pro forma invoice include?

Clearly title it “pro forma invoice” so it is never mistaken for an invoice, and do not give it a number from your invoice series: use separate numbering. Then include both parties' details, itemised prices excl. VAT, VAT, the total, validity period and payment terms.

This information is good practice, not a legal requirement: no mandatory content is prescribed for a pro forma. For actual invoices, the administration's Business Expert Group publishes an example of a compliant minimum invoice.

Does a pro forma invoice go through Peppol?

No. The Peppol sending obligation applies to invoices, and a pro forma is not one: you can email it as a PDF. However, the subsequent deposit or final invoice must go through Peppol if your customer is a Belgian VAT-registered business. Check that they can receive it with our Peppol check guide.

See Peppol check: verify whether a customer is registered and the B2B FAQ, question 14.

What should you do when a customer pays against a pro forma?

As soon as you receive payment before delivery, VAT becomes due on the amount received: you must then issue a real invoice, either a deposit or final invoice, no later than the 15th of the month following receipt. The pro forma cannot serve as an invoice, and the customer cannot deduct VAT based on it.

Sources: VAT Directive, article 65 and FPS Finance. Details, with a worked example, are in our deposit invoice guide.

What about your quotes and actual invoices?

Eazyclick has a dedicated module for quotes and invoices. Eazyclick's Quotes & invoices module creates quotes signed online and invoices sent in Peppol format to your business customers, with payment links and automatic reminders. Book a free call.

Frequently asked questions about pro forma invoices

How long is a pro forma invoice valid?

For as long as you specify: no period is prescribed. Always state a validity date so your customer knows how long the quoted price stands.

Should you number a pro forma invoice?

Yes, so you can find it, but in a separate series from your invoices, to avoid gaps or duplicates in invoice numbering.

Can you turn a pro forma into an invoice?

Yes, by issuing a real invoice with the same content, a number from your invoice series and the invoice date. The pro forma remains an information document.