Billingz Guides · Documents
Pro forma, invoice, credit note: which document, and when
Short answer
Three documents, one sequence. A pro forma comes before the supply and asks to be paid. An invoice records the supply and is the only one of the three that is a tax document. A credit note comes after, when something on an issued invoice has to change. Send the wrong one and either your books or your client’s will be wrong, usually quietly.
The pro forma: a formal ask, not a record
A pro forma looks like an invoice on purpose. It carries the same lines, the same totals, the same VAT rates and your bank details, so a client can approve it internally, put it through procurement, or pay before the work starts. What it does not carry is legal effect.
It creates no VAT liability for you and gives the client no right to deduct VAT. That is not a matter of interpretation, and across Europe the document says so on its face, in the local language: not a tax document, no right to deduction. Germany and Austria put it more plainly still, that this is not an invoice in the sense of VAT law.
- Use it - to request payment in advance, to give a client something approvable, or where customs or a procurement process needs a formal document before supply.
- Do not use it - as a substitute for an invoice once the money has arrived or the work has been delivered. That is the moment the real document is due.
The invoice: the only tax document of the three
The invoice is what the tax authority reads, what your client deducts against, and what your numbering sequence is actually for. It is issued at the point of supply, or on payment where you invoiced in advance, and once it is out it is never edited and never deleted.
Everything else on this page exists to get to it or to correct it. What it has to contain, and how to number it, is a guide of its own: how to make an invoice that gets paid.
The credit note: the only way back
When an issued invoice has to change, a credit note reverses it on the record rather than the invoice being edited or deleted. It is the third position in the sequence, and the only legitimate route backwards.
The anatomy of one, what it must never carry, and what it is called in each country are covered in their own guide: credit notes explained.
The three, side by side
The same sale, in the three documents it can produce. The numbering follows Portugal, which keeps the three series further apart than anywhere else in Europe and prints the difference on every page.
Pro-forma invoice
PF 2026/00001
Not a tax document. No right to VAT deduction.
Lines
Payment details
IBAN PT50 0002 0123 1234 5678 9015 4
Reference: PF 2026/00001
Pro-forma invoice. Asks for money before there is anything to record. Not a tax document, and it says so on its face.
Invoice
FT 2026A/00001
Fiscalised through the national e-invoicing system; this rendering is a readable copy.
Lines
Payment details
IBAN PT50 0002 0123 1234 5678 9015 4
Reference: FT 2026A/00001
Invoice. Records the sale. The only one of the three your client can deduct against.
Credit note
NC 2026A/00001
Refers to invoice FT 2026A/00001 · 01/05/2026 · Reason: Agreed reduction
Lines
Payment details
IBAN PT50 0002 0123 1234 5678 9015 4
Reference: FT 2026A/00001
No payment due date.
Credit note. Reverses the invoice. A tax document in its own right, pointing the other way.
Sample documents. Company names, addresses, numbers and bank details are illustrative.
- The header names the document
- Pro-forma invoice, invoice, credit note. Nobody should have to read a total to work out which of the three they are holding.
- Three series, three prefixes
- PF, FT and NC run separately, the pattern Portugal makes explicit. A pro forma that is never converted therefore leaves no gap in the sequence of tax documents, which is the whole reason the series are kept apart.
- The pro forma disqualifies itself
- Not a tax document. No right to VAT deduction. The document states in its own words what it is not, so nobody files it as something it is not.
- The credit note points back
- It names the invoice it corrects, the date of that invoice, and the reason for the correction. Without those three it is a floating amount nobody can match.
- Even the total changes its name
- Total payable becomes total credit. The figure is identical; the direction is not, and the label is what tells you which.
- One of them asks for nothing
- A pro forma and an invoice carry a due date. A credit note carries none, because nothing is being asked for. The bank details stay only as a reference for the refund.
Three sequences, not one
Each document type runs in its own numbered series, and mixing them is the mistake with the longest tail.
Invoice numbering is a legal sequence of tax documents. Drop pro formas into it and every pro forma that is never converted leaves a gap, because nothing was ever supplied against that number. Gaps are the first thing an auditor asks about, and explaining them years later is unpleasant.
Portugal shows the pattern at its most explicit: pro formas run as PF 2026/00001, invoices as FT 2026A/00001, credit notes as NC 2026A/00001. Different letters, different runs, no ambiguity about which document a number belongs to.
The three mistakes worth naming
- Sending a pro forma and considering yourself paid - the money arrived, but no tax document exists, so the sale is not in your books and your client cannot deduct anything.
- Editing an issued invoice - the correction instrument is a credit note. A quietly re-sent PDF carrying the same number is a mess in most of Europe and a compliance problem in some of it.
- One numbering sequence for everything - it breaks the moment a pro forma goes unanswered, and it cannot be repaired retrospectively.
What a pro forma is called where you are invoicing
PREDRACUN in Croatia, Bosnia, Montenegro and Slovenia. PROFORMA-RECHNUNG in Germany and Austria. FACTURE PRO FORMA in France. FATTURA PROFORMA in Italy. FAKTURA PRO FORMA in Poland. FACTURA PROFORMA in Spain. FATURA PRO-FORMA in Portugal. PROFORMAFAKTURA in Norway. PROFAKTURA across the Western Balkans. In the United States it usually has no special name at all, only a line saying it is not an invoice.
The vocabulary is local. The sequence is not: something asks, something records, something reverses. Get the roles right and the names follow whichever country you are invoicing into.
Common questions
Is a pro forma invoice a real invoice?
No, and that is the whole point of it. A pro forma is a formal offer to be paid: it looks like an invoice so the client can approve it, get it through procurement or pay in advance, but it creates no VAT liability for you and gives the client no right to deduct VAT. Across Europe the document itself says so in a printed line, in the local language.
When the client pays a pro forma, what do I do?
Issue the invoice. That is the step people forget, and it is the one that matters. Payment against a pro forma is money received for a supply that still needs a tax document, so the invoice follows and takes its number from your invoice sequence. Leaving it at the pro forma means the transaction never entered your books properly and your client cannot deduct the VAT.
Can I number a pro forma in the same sequence as my invoices?
No. Invoice numbering is a legal sequence of tax documents, and a pro forma is not one. Putting it in the same run creates a gap when a pro forma is never converted, and gaps are exactly what an auditor asks about. Pro formas take their own series, which is why you see forms like PF 2026/00001 alongside FT 2026A/00001 for invoices and NC 2026A/00001 for credit notes.
Do I have to keep pro formas if they are not tax documents?
Keep them. They are not tax documents, so they do not go into the VAT record, but they are the evidence of what was agreed and what a payment received in advance related to. When a bank asks for the basis of an incoming foreign payment, or a client queries what they approved months ago, the pro forma is the document that answers. Storage costs nothing and the alternative is reconstructing an agreement from memory.
Is a pro forma the same as a quote?
Close, but not identical. A quote proposes terms and invites negotiation. A pro forma states settled terms and asks for payment on them, which is why it carries totals, VAT rates and bank details. In practice a quote becomes a pro forma once both sides agree, and the pro forma becomes an invoice once money moves or the work is delivered.
What is a pro forma called in other countries?
The name changes and the function does not. PREDRACUN in Croatia, Bosnia, Montenegro and Slovenia; PROFORMA-RECHNUNG in Germany and Austria; FACTURE PRO FORMA in France; FATTURA PROFORMA in Italy; FAKTURA PRO FORMA in Poland; FACTURA PROFORMA in Spain; FATURA PRO-FORMA in Portugal; PROFORMAFAKTURA in Norway; PROFAKTURA across the Western Balkans. In the United States it is usually labelled simply as not an invoice, for information only.
Built for this
Billingz issues all three in the form each country expects, in its own numbered series, with the pro forma carrying the statutory line that it is not a tax document, and a pro forma converts into an invoice without retyping anything.
See how Billingz handles documentsThis guide is general information, not tax advice. Document names and statutory notes are compiled from national VAT laws and tax-authority guidance for the markets Billingz covers, as verified in August 2026. Rules, names and numbering requirements vary by country and change over time; Billingz does not warrant that this page reflects the rules on the day you read it. Confirm specifics with a qualified accountant.