What is a Proforma Invoice?

A proforma invoice is a preliminary document sent by a seller to a buyer before goods or services are delivered. It outlines the expected costs and terms of a transaction but does not constitute a demand for payment. In UK business practice, proforma invoices serve as formal quotations, pre-shipment documents and planning tools.

How a proforma invoice differs from a standard invoice

The key distinction is that a proforma invoice has no legal standing as a tax document. It cannot be used to claim VAT input tax and should not be recorded as revenue or an expense in the accounts.

For details on what a standard UK invoice must contain, see what an invoice is .

When UK businesses use proforma invoices

Pre-payment requests

Some businesses require payment before delivering goods, particularly for new customers without an established credit history. A proforma invoice tells the buyer exactly what to pay before the order is fulfilled.

International trade and customs

Proforma invoices are widely used in cross-border transactions for:

• Customs declarations where authorities need to assess duties and taxes before goods arrive
• Import licensing where the buyer needs documented evidence of the intended purchase
• Letter of credit applications where banks require a formal description of the transaction
• Foreign exchange where the buyer needs to arrange currency conversion

When dealing with international payments, the proforma should include the seller’s IBAN and BIC/SWIFT details.

Internal approval processes

Large organisations often circulate proforma invoices internally for budget approval before committing to a purchase. This fits into the broader purchase order workflow where spending must be authorised before orders are placed.

Quotation and negotiation

A proforma invoice can function as a detailed quotation, providing more structure than a simple quote. It gives the buyer a clear picture of costs, payment expectations and delivery arrangements before they commit.

What to include on a proforma invoice

Although not legally required to follow the same format as a VAT invoice, a well-prepared proforma invoice should include:

• Clear labelling as “Proforma Invoice” prominently displayed
• Seller’s business name, address and contact details
• Buyer’s name and address
• Date of issue
• Description of goods or services in sufficient detail
• Quantities and unit prices
• Total amount including any applicable VAT indication
• Proposed payment terms (see payment terms )
• Estimated delivery date or timeline
• Validity period stating how long the proforma remains valid
• Currency (GBP for domestic, or the agreed currency for international)
• Incoterms if applicable to international shipments

Marking and clarity

It is critical that a proforma invoice is clearly marked as such. If a document looks like an invoice but is actually a proforma, confusion can arise in the buyer’s accounts payable team, potentially leading to:

• Premature payment before goods are delivered
• Incorrect VAT claims based on a non-tax document
• Double-counting if a real invoice follows

Proforma invoices and VAT

HMRC does not recognise proforma invoices as VAT invoices. This has several important implications:

• The seller must not include the proforma in their VAT return output calculations
• The buyer cannot reclaim VAT based on a proforma invoice alone
• A proper VAT invoice must be issued once the transaction is completed
• If payment is received against a proforma, the VAT point is triggered and a proper invoice should be raised promptly

Tax point considerations

In the UK, the tax point (the date VAT becomes chargeable) is generally the earlier of:

• The date goods are delivered or services performed
• The date payment is received

If a customer pays against a proforma invoice, this receipt creates a tax point. The seller must then issue a proper VAT invoice within 30 days and account for the VAT in the relevant return period.

Accounting treatment

Since a proforma invoice is not a financial document for accounting purposes:

• Do not debit or credit any ledger accounts when issuing or receiving a proforma
• Do not include proformas in aged receivable or payable reports
• Do keep proformas on file for reference and audit trail
• Do issue a proper invoice when the transaction is completed

The real accounting entries occur only when the actual invoice is raised. At that point, the standard entries for revenue recognition and receivables apply, as described in our overview of accounting principles .

Proforma invoices in practice

Workflow for a typical proforma transaction

1. Buyer requests a quotation or the seller identifies a proforma is appropriate
2. Seller prepares and sends the proforma invoice
3. Buyer reviews, obtains internal approval and arranges payment or confirms the order
4. Seller receives confirmation or payment
5. Seller fulfils the order (delivers goods or performs services)
6. Seller issues a proper VAT invoice referencing the proforma
7. Both parties record the transaction in their accounts based on the VAT invoice

Converting a proforma to a real invoice

Most accounting software allows you to convert a proforma into a standard invoice. When doing so:

• Assign a proper sequential invoice number from your sales ledger
• Update the date to reflect the actual invoice date
• Verify the amounts, quantities and VAT match the delivered goods or services
• Remove the “Proforma” label and replace with standard invoice headings
• Include all mandatory invoice fields required under UK law

Common mistakes with proforma invoices

• Recording proformas as revenue which overstates sales and creates VAT liability prematurely
• Not issuing a proper invoice after delivery leaving the transaction without a valid tax document
• Using proforma numbering in the invoice sequence which creates gaps or confusion in the sales ledger
• Failing to state a validity period which can lead to disputes if prices change
• Omitting the “Proforma Invoice” label causing the buyer to treat it as a real invoice

Proforma invoices vs other preliminary documents

Each document serves a distinct role in the commercial cycle. Proforma invoices bridge the gap between quotation and formal invoicing, particularly useful when upfront payment or customs documentation is needed.