Proforma invoicing: how, what and why in accounting

Lee Latter

min

Contents

A proforma invoice is one of the most commonly misunderstood documents in business finance. Used correctly, it speeds up procurement, supports international trade, and gives buyers the clarity they need to approve a purchase. Used incorrectly, it creates confusion in accounting records and compliance headaches at audit time. This guide sets out what proforma invoices are, how they are recorded, and where they fit in the reconciliation process.

Summary

A proforma invoice is a preliminary document sent before a sale is finalised. It is not a demand for payment and not legally binding.
Proforma invoices are not VAT invoices and must carry the statement “This is not a VAT invoice”. They do not create a tax point and cannot be used to reclaim VAT.
They are widely used in international trade, advance payment scenarios, and procurement approvals.
HMRC processed 91.3 million customs declarations for international trade in goods in 2025, the majority of which require supporting invoice documentation including proforma invoices at the pre-shipment stage.
Proforma invoices do not appear in the accounts receivable ledger and should not be included in reconciliation as confirmed revenue.
Reconciliation in accounting should be based on confirmed VAT invoices, not proforma documents.

What is proforma invoicing?

A proforma invoice is a preliminary document issued by a seller to a buyer before a transaction is complete. It sets out the expected goods or services, quantities, prices, and terms so the buyer can review and approve them before committing. It looks like a standard invoice but carries a critical distinction: it is not a VAT invoice, not legally binding, and does not create a tax point.

Because a proforma is not a VAT invoice, the seller does not owe VAT to HMRC on the basis of it alone, and the buyer cannot use it to reclaim VAT. HMRC requires that any proforma invoice prominently states "This is not a VAT invoice" to prevent it being mistakenly used in VAT accounting. VAT liability only arises when goods are delivered, services are performed, or a payment is received against a formal VAT invoice.

Proforma invoicing vs commercial invoicing

The distinction between a proforma invoice and a commercial invoice is fundamental.

A proforma invoice is issued before a transaction is confirmed. It is an estimate or offer, not a demand for payment. It has no legal standing, does not affect accounts receivable, and does not trigger VAT. It exists to give the buyer the information needed to approve a purchase.

A commercial invoice is issued after goods or services have been delivered. It is a formal demand for payment, legally binding, and in most cases a valid VAT invoice that creates a tax point. It appears in accounts receivable and forms part of the reconciliation process.

For customs purposes, a commercial invoice is the document required to accompany goods across borders. A proforma may be used at the pre-shipment stage to estimate duties and obtain import licences, but it is replaced by the commercial invoice when goods are shipped.

How do you record a proforma invoice in accounting?

The short answer is: you do not record a proforma invoice as a transaction in your accounting system. Because it is not a confirmed sale, not legally binding, and does not create a tax point, it has no place in the accounts receivable ledger or the VAT return.

What this means in practice:

No journal entry is posted when a proforma is issued.
The proforma does not appear in accounts receivable aging reports.
No VAT is reported to HMRC on the basis of the proforma.
Revenue is not recognised until a formal VAT invoice is raised and goods or services are delivered.

Some businesses track proforma invoices in a separate register or CRM system to monitor outstanding quotes and expected orders. This is good practice for pipeline visibility, but it sits outside the accounting system. When a proforma is accepted and the order confirmed, a formal VAT invoice replaces it and that invoice is recorded in the usual way.

Understanding the difference between documents that trigger accounting entries and those that do not is covered in detail in our guide to common accounting terms.

When you may need to issue a proforma invoice

International trade and customs. Proforma invoices are standard in cross-border trade. They allow importers to estimate duties, apply for import licences, and arrange letters of credit before goods are shipped. HMRC's customs data shows 84.6 million customs declarations were processed in 2024, with the vast majority requiring invoice documentation at some stage of the import or export process. In payments industry contexts, they are also used to confirm expected payment amounts before cross-border transfers are initiated.

Advance payments and deposits. Where a seller requires payment before goods are produced or delivered, a proforma invoice sets out the amount due and the payment terms. The buyer uses it to authorise the payment internally and arrange transfer. Once payment is received and goods are delivered, a formal VAT invoice is issued to complete the transaction.

Procurement approvals and budgeting. Many organisations require a formal document to support a purchase order or budget approval before committing to a supplier. A proforma invoice provides the pricing detail needed for internal sign-off without creating a liability in the accounts until the purchase is confirmed. This is particularly common in property management contexts, where large-value works require board or committee approval before contracts are signed.

Proforma invoicing and reconciliation

Proforma invoices should not be part of the accounts receivable reconciliation process. Because they are not confirmed transactions, they do not appear in the AR ledger, and including them in reconciliation would overstate the business's receivables position and distort cash flow reporting.

The reconciliation process should be driven by confirmed VAT invoices, payment records, and bank statement data. When a proforma is superseded by a formal invoice, that transition is the point at which the transaction enters the accounting system and becomes subject to reconciliation.

However, proforma invoices can create indirect reconciliation challenges if they are not properly managed. Common issues include:

Finance teams mistakenly include proforma totals in revenue forecasts or DSO calculations.
Proforma invoices being filed alongside VAT invoices in document management systems, causing confusion during audit.
Customers paying against a proforma without a formal VAT invoice being raised, leaving cash applied but no matching AR entry.

The last scenario is particularly important: if a customer pays on the basis of a proforma, the incoming cash will appear in the bank statement but will not match any open invoice in the AR ledger. This creates unapplied cash that distorts the reconciliation until a formal invoice is raised and matched. Automated reconciliation tools can flag this as an exception immediately, rather than leaving it to be discovered at month-end. Reconciliation in accounting requires clean, confirmed source documents, and proforma invoices are not that.

One of the most consistent reconciliation issues we see is cash applied against proforma invoices where no formal VAT invoice was ever raised. The payment is real, the liability is real, but the accounting record is missing. Automated matching surfaces this immediately, whereas manual processes can leave it unresolved for weeks.”

Lee Latter, Head of Professional Services, Aurum Solutions

At Aurum, we help finance teams automate reconciliation across payment rails and invoice systems, ensuring that exceptions like unmatched proforma payments are surfaced and resolved quickly. Book a demo to see how automated reconciliation can strengthen your month-end process.

Proforma invoicing FAQs

Is proforma invoicing legally binding?

No. A proforma invoice is not a legally binding document. It does not constitute a contract, a demand for payment, or a VAT invoice. The seller is not obligated to supply goods or services at the stated price, and the buyer is not obligated to pay. Legal and financial obligations arise only when a formal commercial or VAT invoice is issued, typically on delivery of goods or completion of services.

Common mistakes with proforma invoices

The most frequent mistakes are treating proforma invoices as VAT invoices (they are not and must state this clearly), recording them in accounts receivable before a sale is confirmed, allowing customers to use them to reclaim VAT (HMRC does not permit this), and failing to replace them with a formal invoice after payment or delivery. In international trade, sending only a proforma without issuing a commercial invoice at shipment is also a common customs compliance error.

Do I pay VAT on a proforma invoice?

No. A proforma invoice does not trigger a VAT liability for the seller and cannot be used by the buyer to reclaim VAT. VAT becomes due when a tax point is created, which happens either when goods are delivered, services are completed, or a VAT invoice is issued, whichever comes first. A proforma does not trigger any of these events. If you are VAT-registered, you may show an estimated VAT amount on the proforma for the buyer’s reference, but the document must still carry the statement “This is not a VAT invoice” and cannot be used as the basis for a VAT claim.

At Aurum Solutions, we are committed to upholding fiscal responsibility in all our financial endeavours. We prioritise prudent financial management, transparency, and accountability to ensure the effective allocation and utilisation of resources. Our commitment to fiscal responsibility extends to our stakeholders, fostering trust and sustainability in our financial practices.

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