Definitions
An invoice records a completed sale or supply and asks for payment. It is a tax and accounting document: it goes into your sales ledger, it carries the legally required fields for your country, and in VAT systems it lets a business buyer reclaim the VAT.
A proforma invoice is a preview of that invoice. It lists the same seller, buyer, items, prices and taxes, but it is issued before the sale is final. It carries no tax effect, it is not entered as revenue, and the buyer cannot use it to reclaim VAT.
Proforma vs invoice at a glance
| Proforma invoice | Invoice | |
|---|---|---|
| Purpose | Announce the terms; request prepayment; support customs or financing | Request payment for goods or services supplied |
| Legal status | Commercial document, not a tax invoice | Tax and accounting document |
| Tax | Shows expected tax for information; no VAT reclaim | Shows tax due; business buyer may reclaim VAT |
| Numbering | Own series (PF-…), outside the invoice sequence | Unique sequential invoice number |
| Accounting | Not booked as revenue or receivable | Booked as revenue and receivable |
| Payment | Buyer may pay in advance on the strength of it | Buyer pays by the due date |
| Title | “Proforma invoice” plus “This is not a tax invoice” | “Invoice” or “Tax invoice” |
When to use a proforma invoice
- Prepayment. You ship or start only after payment. The proforma tells the buyer exactly what to transfer.
- International trade and customs. Importers often need a proforma to apply for an import license, arrange a letter of credit or clear samples and free goods. For the actual shipment, a commercial invoice is the usual customs document.
- Formal price confirmation for foreign buyers. Some buyers’ procurement teams want a document that looks like the final invoice before they release funds.
- Countries where only e-invoices count. In Italy, business invoices must go through the national e-invoicing system (SdI). In Belgium, since 1 January 2026 invoices between Belgian VAT-registered businesses must be structured Peppol e-invoices. A PDF from a browser tool is not a valid invoice in those cases, so our editor shows ✕ in the verdict card and suggests a proforma or a quote instead. You then issue the real invoice through your e-invoicing provider.
If the price is still under discussion, a quote or estimate is the better document.
A worked example
A Dutch maker of ceramic lamps sells 200 lamps to a shop in Rotterdam and asks for payment before production.
Proforma invoice PF-2026-007 (dated 4 May 2026):
| Description | Qty | Unit price | Amount |
|---|---|---|---|
| Ceramic table lamp, white | 200 | €18.50 | €3,700.00 |
| Subtotal | €3,700.00 | ||
| btw 21% | €777.00 | ||
| Total | €4,477.00 |
Maths: 200 × €18.50 = €3,700.00; 21% of €3,700.00 = €777.00; €3,700.00 + €777.00 = €4,477.00.
The shop pays €4,477.00 on 11 May. The maker then issues invoice 2026-041 with the same lines, the next number in the invoice series, the delivery or payment date, and the full Dutch invoice details (btw-id, KvK number and so on). The proforma stays in the file as a reference but never enters the sales ledger.
How to convert a proforma into an invoice
- Wait for the trigger: payment received, goods shipped, or service delivered, depending on your agreement and local rules.
- Open the invoice generator and create an invoice for the same client. Saved clients and saved items make this quick, since nothing needs to be retyped.
- Use the next invoice number from your invoice series, never the proforma number.
- Set the correct issue date and the date of supply or of the prepayment where your country requires it.
- Add “Paid on 11 May 2026” or show the amount already received, so the client does not pay twice.
- Mark the proforma as superseded in your records.
What to put on a proforma invoice
A proforma works best when the buyer can pay, apply for a licence or plan a shipment from it without asking follow-up questions. Before you send one, check that it has:
- Your details and the buyer’s, written exactly as they will appear on the final invoice, including any VAT or business number.
- A proforma number and date from the PF series, so both sides can refer to it in emails and bank transfers.
- Full item descriptions with quantity, unit price and currency. For cross-border goods, add weight, country of origin and the incoterm if the buyer’s bank or customs broker needs them.
- Expected tax, shown for information, and the total the buyer should transfer.
- Payment details and a validity date, for example “Prices valid until 31 May 2026”. After that date you are free to requote.
- The not-a-tax-invoice line described below.
The wording to use
Put a clear title and a short line on every proforma so nobody books it as an invoice:
- “Proforma invoice”
- “This is not a tax invoice.” or “This document is not an invoice for VAT purposes.”
- Optionally: “A tax invoice will be issued upon payment.”
The proforma editor adds the title and a suitable note for your country automatically.
Common mistakes
- Using the invoice number series. It creates a gap or duplicate in your real invoices. Keep proformas in their own series; see invoice numbering.
- Booking it as revenue. Only the final invoice belongs in the sales ledger.
- Forgetting the final invoice. The buyer needs it for their books and VAT reclaim.
- Calling it a tax invoice. In Australia, for example, only a document from a GST-registered seller should carry that title.
- Leaving out details the final invoice will need. If the proforma already has complete invoice fields, the conversion is copy-and-renumber.