Key takeaways
- A pro forma invoice is a provisional, informational document issued before the final invoice.
- It has no accounting or tax value: no official number, no accounting entry, no VAT chargeable.
- It does not let the customer deduct VAT; only the final invoice opens that right.
- You use it to confirm an order, request a down payment, or accompany an international shipment.
The pro forma invoice, an informational document with no accounting value
The term comes from the Latin pro forma, "as a matter of form". A pro forma invoice says as much: it has the appearance of an invoice, it often copies its layout, but it does not produce its effects. It is a provisional commercial document, given to the customer before the sale is finalised, to set out in writing the detail of what will be invoiced.
In practice, it shows the same information as an ordinary invoice: the identity of the seller and the customer, the description of the goods or services, the quantities, the unit prices, the estimated VAT and the total amount. The difference is not in what it contains, but in what it triggers: nothing, in accounting and tax terms.
This article explains what a pro forma invoice does, what it does not do, and how not to confuse it with a final invoice or a quote.
Pro forma invoice or invoice: the differences that matter
The most common confusion is to treat a pro forma as an invoice because it looks like one. Yet they are documents of a different nature. A final invoice is an accounting record: it carries a number from the company's official, continuous sequence, it is recorded in the accounts, it makes the VAT chargeable and it lets a taxable customer deduct that VAT. A pro forma invoice ticks none of these boxes.
| Pro forma invoice | Final invoice | |
|---|---|---|
| Sets out the sale detail (items, prices, VAT) | ||
| Carries a number from the official invoice sequence | ||
| Is recorded in the accounts | ||
| Makes the VAT chargeable | ||
| Lets the customer deduct VAT |
A practical consequence follows: a pro forma must never carry a number from your invoice sequence. Number it separately if you wish, and clearly mark the words "pro forma invoice" or "pro forma" on the document. That prevents it from being taken for a real invoice, booked by mistake, or presented to the authorities as a supporting document.
What a pro forma invoice is for
If it has no accounting value, why issue one? Because it plays a role of information and preparation, ahead of the final invoice. It gives the customer a firm document to rely on before the transaction is closed.
The situations where a pro forma is useful
Confirm an order or an accepted quote
The customer has the exact priced detail before delivery or performance.
Request a down payment
The pro forma serves as the basis for the payment; the invoice itself follows the rules specific to a down payment.
Accompany an international shipment
It can travel with the goods and give an indicative value where no commercial invoice yet exists; the customs value itself is the transaction value from the commercial invoice.
Prepare a payment or financing
The customer can start an internal request, a transfer or a financing file on this basis.
In every one of these cases, the pro forma is only a step. Once the down payment is received, the order delivered or the service performed, it is the final invoice that is drawn up, recorded and sent. For the rules specific to advance payments, see The down payment invoice in Belgium.
Pro forma invoice and VAT: what it does not trigger
This is the most important point, and the most often misunderstood. A pro forma invoice and VAT do not mix: the document has no effect on the tax.
For the issuer, this means VAT does not have to be declared on the basis of a pro forma. For the recipient, it means they must wait for the final invoice to exercise the right to deduct and to file the document in their accounts. The VAT shown on a pro forma is an indicative estimate, not a tax due. For what an invoice that does produce those effects must contain, see The mandatory invoice details in Belgium.
Pro forma, quote and final invoice: do not confuse them
Three documents often accompany the same sale, in this order: the quote, the pro forma invoice, then the final invoice. They look alike, but each has a distinct function. The quote is a commercial offer, usually before the customer agrees. The pro forma comes later, once the details are settled but the invoice is not yet due. The final invoice closes the cycle: it is the only accounting and tax record.
In practice, many businesses go straight from the quote to the invoice, with no pro forma. That is not a problem: the pro forma is an optional tool, to be used when it adds something (a down payment to request, a customs office to satisfy, a customer to reassure), not a mandated step.
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What it changes for your invoicing
Keeping the distinction avoids two common mistakes. The first is booking a pro forma as an invoice, which distorts your VAT and your numbering sequence. The second is the opposite: believing that a pro forma is enough to claim a payment or justify a deduction. In both cases the rule is simple: the pro forma prepares, the final invoice commits.
This distinction holds in the age of structured e-invoicing. The B2B e-invoicing mandate in Belgium applies to the final invoice, not to the informational documents that precede it. A pro forma can stay a plain PDF or a printed document; it is the final invoice that will have to travel in the structured format. For the timing and scope of that mandate, see Peppol in Belgium: the B2B mandate on 1 January 2026.
Further reading
- The down payment invoice in Belgium: the VAT rules when a payment precedes delivery.
- The mandatory invoice details in Belgium: what a final invoice must contain.
- Peppol in Belgium: the B2B mandate on 1 January 2026: which invoices move to the structured format, and when.
For the official reference on VAT accounting and invoicing, see the FPS Finance.
What is a pro forma invoice?
A pro forma invoice is a provisional commercial document that sets out the details of an intended sale (items, quantities, prices, estimated VAT, total) before the final invoice is issued. It informs the customer, but has no accounting or tax value: it is not recorded in the accounts and does not make the VAT chargeable.
What is the difference between a pro forma invoice and an invoice?
A final invoice carries a number from the official sequence, is recorded in the accounts, makes the VAT chargeable and lets the customer deduct it. A pro forma invoice often repeats the same information, but remains an informational document: it carries no official number, does not enter the accounts and opens no right to deduct VAT.
Can you deduct VAT with a pro forma invoice?
No. The right to deduct VAT requires an invoice compliant with the VAT Code. A pro forma invoice is not an invoice in the tax sense, so it does not let the customer deduct VAT. Only the final invoice, issued once the sale is complete, opens that right.
When should you issue a pro forma invoice?
You issue a pro forma invoice to confirm the details of an order, request a down payment, accompany an international shipment, or let the customer prepare a payment or financing. It serves as a reference document before the final invoice is drawn up.
Is a pro forma invoice mandatory?
No. The pro forma invoice is optional: it is a commercial tool, not a legal requirement. The final invoice, on the other hand, is mandatory whenever a transaction is subject to that requirement. A pro forma never replaces the final invoice and does not remove the obligation to issue one.
