When do you need a proforma invoice? 7 common business scenarios

A proforma invoice is a preliminary document that states what a seller intends to charge before a transaction is complete. It carries no legal payment obligation and cannot be used for accounting entries or tax credit claims. Knowing when a proforma is the correct document — rather than a quotation, a commercial invoice, or an order confirmation — prevents compliance errors and avoids confusion with buyers.

1. Import and export customs clearance for unconfirmed shipments

When goods cross a border before a sale is finalised — such as samples sent for evaluation, goods shipped on consignment, or items sent for repair and return — customs authorities require a document that declares the shipment's contents and indicative value for duty assessment purposes. A commercial invoice is not appropriate because no sale has occurred and no payment is owed.

A proforma invoice fills this role. It states the description, quantity, unit value, and total value of the goods purely for customs declaration purposes. The World Customs Organization's glossary explicitly recognises proforma invoices as valid customs documents in non-commercial shipment scenarios. Note that for completed commercial sales, customs requires a commercial invoice — a proforma is not a substitute.

2. Advance payment requests before work begins

Many service providers and manufacturers require partial or full payment before beginning work, particularly for custom orders or large projects. A proforma invoice is the standard document used to request this advance payment. It communicates the amount due, the bank details for payment, and the scope of work to be performed — without creating the accounting entry that a commercial invoice would trigger.

The buyer pays against the proforma. Once work is complete and delivery is made, the seller issues a commercial invoice for the balance (or marked as paid if the advance covered the full amount). This sequence is important for accounting: the proforma request precedes the commercial obligation.

3. Quotation confirmation for international buyers

A standard sales quotation is informal and may not carry enough detail for an international buyer's procurement or import documentation process. A proforma invoice, formatted with the seller's full details, the buyer's details, itemised line items, Incoterms, port of loading and discharge, and estimated shipping dates, provides everything the buyer's import department needs to begin the import process — including applying for an import licence or foreign exchange allocation in countries with currency controls.

In markets where import permits are required before goods can enter the country, a proforma invoice from the foreign seller is a mandatory submission document. It commits neither party to a final price but provides sufficient detail for official approval processes.

4. Project kickoffs requiring purchase order issuance

Corporate buyers with formal procurement processes often cannot issue a purchase order until they have received a detailed document from the supplier specifying exactly what will be supplied and at what price. A proforma invoice provides the detail needed to raise a PO through the buyer's internal systems. Once the PO is issued, the seller proceeds with the work and eventually issues a commercial invoice referencing the PO number.

5. Samples and gifts with no commercial value

When sending product samples to a potential customer — particularly across international borders — the goods have no commercial value in the transactional sense but do have a declared value for customs. A proforma invoice stating the items, their indicative value ("for customs purposes only — no commercial value"), and a note that no payment is required allows customs to process the shipment and assess any applicable duties without the shipment being treated as a commercial sale.

Many countries have de minimis thresholds below which samples are duty-free. The proforma invoice provides the declared value that determines whether the threshold applies.

6. Letter-of-credit transactions

A letter of credit (LC) is a payment mechanism used in international trade where a buyer's bank guarantees payment to the seller, provided the seller presents specified documents. Before the LC is opened, the buyer's bank requires the buyer to submit documents specifying exactly what is being bought, at what price, and under what terms. The proforma invoice is the primary document used for this purpose.

The LC terms are drafted directly from the proforma: the description of goods, the unit price, total value, Incoterms, currency, port of shipment, and latest shipment date all appear in the LC because they appeared first in the proforma. Any discrepancy between the proforma and the commercial invoice later presented under the LC can result in the bank refusing payment — making accuracy in the proforma critically important.

7. Internal cost estimates and budget approvals

Some organisations use proforma invoices as internal budget documents — a structured estimate of expected costs for a project or purchase, formatted as an invoice-like document for presentation to a finance committee or board. This usage is informal (a proforma used this way has no external legal status) but common in project-driven businesses where budget approval requires a detailed cost breakdown in a standardised format.

In this scenario, the proforma is essentially a formal internal estimate. When the purchase proceeds and the actual supplier invoice arrives, the finance team compares it against the proforma to verify the cost was within the approved budget.