Learn about What Is a Pro Forma Invoice and When Should You Use One. This comprehensive guide covers everything you need to know for beginners.
30 Apr 2026
Inzo
TL;DR: Most pro forma invoice guides stop at the definition. This one covers when to issue one, when a different document is the right call, and what goes wrong operationally if you mix it up with a commercial invoice including the customs scenario that causes the most real-world delays. You'll leave with a clear decision framework, not just a definition.
A pro forma invoice is a document you send before a sale is confirmed. It states the price, quantity, and terms you're committing to, but it is not a payment demand and creates no accounts-receivable entry. Get this distinction wrong and you'll either bill for work a buyer hasn't approved or stall a shipment at customs. This article covers what a pro forma invoice is, how it differs from a commercial invoice, what to include, when to use one, and how to create it.
A pro forma invoice is a preliminary document that confirms what a deal looks like before either party has performed. It gives the buyer enough information to act approve a budget, arrange financing, or clear a shipment through customs without creating a legal obligation to pay.
What it is not: a quote (which carries no commitment), a purchase order (which comes from the buyer), or a contract (which requires acceptance and consideration). It sits between a quote and a commercial invoice in the deal lifecycle.
Once delivery happens and payment is owed, you issue a commercial invoice. Continuing to use a pro forma at that stage creates ambiguity about whether payment is actually due.
The simplest way to separate these two documents: one is a promise, the other is a demand.
A pro forma invoice tells a buyer what they will owe if they proceed. No payment obligation is attached. A commercial invoice tells a buyer what they do owe, creates a legal record of the transaction, and triggers accounts payable.
Both documents can look nearly identical on paper line items, quantities, unit prices, totals. The difference is legal standing, not layout. A commercial invoice is a binding financial instrument. In most jurisdictions, including the UK, US, and EU, it can be used as evidence in a contract dispute or debt recovery claim. A pro forma invoice carries no equivalent weight. It confirms intent, not obligation.
This is why substituting one for the other creates problems. Send a commercial invoice before a buyer has approved scope and you're billing for work they haven't committed to. Send a pro forma to your accounts team as the basis for a payment run and nothing will move it won't pass a standard three-way match in any ERP system.
The handoff point is approval. Before a buyer confirms the order, scope, or shipment terms, you're in pro forma territory. After confirmation, you switch to a commercial invoice.
For an IT services contract, that looks like this: you send a pro forma when a client requests a cost breakdown before signing. Once they approve the milestone or purchase order, you issue a commercial invoice against it. The pro forma doesn't get replaced it becomes the reference document the commercial invoice fulfills.
Pro forma invoice | Commercial invoice | |
|---|---|---|
When issued | Before sale is confirmed | After goods delivered or services rendered |
Payment obligation | None | Yes, legally binding |
Accounts payable trigger | No | Yes |
Customs use | Samples, temporary exports, pre-sale shipments | Completed sales where title transfers |
Legal standing | Confirms intent | Binding financial instrument |
For cross-border shipments, the same logic applies. A pro forma goes to customs when the goods haven't been sold yet samples, repairs, temporary exports. A commercial invoice goes when title transfers and payment is expected. Using a pro forma for a completed sale at customs can trigger delays or reclassification.
A pro forma invoice doesn't need to be complex, but missing even one field can cause a buyer to delay payment approval or a shipment to stall at customs.
Seller and buyer details : Full legal name, address, and contact information for both parties. For cross-border deals, include your tax ID or VAT number.
Itemized description of goods or services : Each line item needs a clear description. For physical goods, add the HS (Harmonized System) code and country of origin customs authorities require both. For IT services or software, describe the deliverable specifically: "12-month SaaS license, 50 seats" is more useful than "software subscription."
Unit price, quantity, and line totals : Break these out separately. A lump sum creates questions; an itemized list closes them.
Currency : State it explicitly USD, GBP, EUR. Don't leave the buyer to assume.
Total estimated value :This is the declared value customs uses if the pro forma is submitted as a supporting document. Round numbers or vague estimates will get flagged.
Payment terms : Net 30, 50% upfront, milestone-based whatever applies. This sets expectations before a commercial invoice arrives.
Shipping and delivery terms : Include Incoterms (FOB, CIF, DAP) for any cross-border shipment. These determine who bears risk and cost at each stage of transit.
Validity period : A pro forma without an expiry date creates ambiguity. Most teams set 15 to 30 days.
Reason for export : (for international shipments). "Sale of goods," "temporary import," or "sample no commercial value" are common entries customs expects to see.
A pro forma invoice fits four specific situations. Using it outside those situations is where billing confusion starts.
Before a deal closes, a buyer needs to know exactly what they're committing to. A pro forma invoice sets out the price, scope, and terms so both sides are aligned before any obligation exists. This is standard practice in IT services contracts, where scope can shift between the first conversation and the signed agreement.
When a commercial invoice isn't yet available, many customs authorities including US Customs and Border Protection (CBP) and HMRC in the UK accept a pro forma invoice to establish declared value and shipment details. For a pro forma invoice for customs to clear, it typically needs to include the HS commodity code, country of origin, declared value in the shipment currency, and a description specific enough for classification. Missing any of these fields can stall a shipment.
US CBP generally allows a pro forma for informal entries under $2,500. UK HMRC and EU customs authorities follow similar thresholds for low-value consignments, though the exact figures vary by commodity and origin. The practical rule: use a pro forma invoice for customs only when no binding sale has been finalized. The moment a buyer commits to payment, switch to a commercial invoice.
Finance teams often need a document to raise a purchase order or get sign-off before a vendor can issue a real invoice. A pro forma gives procurement something formal to work with without triggering a payment obligation prematurely.
In fixed-scope or phased projects, a pro forma invoice outlines what each milestone will cost before the work begins. This is especially common in software development and IT infrastructure projects, where clients need cost visibility across a multi-month engagement.
Each scenario shares one thing: the deal isn't done yet, and the document needs to reflect that.
Creating a pro forma invoice takes less time than most IT owners expect, especially if you already have a quote or estimate template in place. The goal is a document that gives your client everything they need to get internal approval, arrange payment, or clear customs, with no ambiguity about what they're buying or what it will cost.
Your full legal business name, address, and tax or registration number. Your client's company name, billing address, and the name of the contact who requested the quote.
Number pro forma invoices in a separate sequence from your final invoices. Use a prefix like PF-2025-001 instead of INV-2025-001. Add the issue date and the expiry date.
Thirty days works for most B2B IT deals. Shorten it if your pricing depends on a variable cost, such as fluctuating SaaS seat pricing or hardware subject to supply chain changes. When it expires, reissue rather than letting the client reference outdated figures.
Write out each line item in full. "Microsoft 365 Business Premium, 10 seats, 12-month subscription" rather than "software setup." Include quantity, unit price, line total, and currency on every line.
For services, state the deposit percentage, balance due date, and accepted payment methods. For hardware crossing a border, add Incoterms. The most common for IT exports are EXW (buyer handles all shipping from your location) and DAP (you cover costs until goods reach the buyer's named destination).
Mark the document "Pro Forma Invoice" at the top. Add a short line such as: "This document is issued for estimation and approval purposes only and does not constitute a tax invoice." This prevents your client's accounts payable team from processing it as a payable.
PDF prevents accidental edits and gives your client a stable file for their internal approval request. Keep a copy linked to the corresponding deal. When the client confirms, your final invoice should mirror the pro forma line for line. If anything changed during negotiation, update the pro forma first, get written confirmation, then issue the final invoice.
If your invoicing software supports document conversion, build the pro forma once and promote it to a final invoice when the deal closes. That single step removes the most common source of billing errors on IT projects: the gap between what was quoted and what was charged.
Q. What is the purpose of a pro forma invoice?
A. A pro forma invoice tells a buyer exactly what they'll owe before the transaction is finalized. Sellers use it to request advance payment, help buyers arrange financing, or satisfy customs requirements for international shipments.
Q. What is the difference between a pro forma invoice and a commercial invoice?
A. A pro forma invoice is a preliminary document with no payment obligation. A commercial invoice is issued after the sale closes and serves as the official request for payment. One sets expectations; the other creates a legal record.
Q. Can I use a pro forma invoice for customs declaration?
A. It can support a customs declaration but cannot replace a commercial invoice for final clearance. Once the transaction is complete, customs requires a commercial invoice with the actual price, quantity, and terms.
Q. How do I create a pro forma invoice?
A. Include your business details, the buyer's name and address, a unique reference number, and the issue date. List each item with quantities, unit prices, and totals, then add taxes, shipping costs, and payment terms. Invoicing software lets you build this from an estimate and export it as a PDF in one step.
Q. Does a pro forma invoice need to be paid?
A. No. It states expected costs but creates no payment obligation. Payment only becomes due once you issue a commercial or final invoice after the transaction is agreed.
Q. Is a pro forma invoice legally binding?
A. No. It outlines expected costs and terms before a transaction is confirmed, so neither party is obligated to complete the sale based on it.
A pro forma invoice does one thing well: it sets expectations before money changes hands. Get the line items, taxes, and client details right upfront, and the final invoice becomes a formality. If your current process involves copying data between documents, start with a tool that handles both steps in one workflow.
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