Proforma Invoice: What to Include, How to Write One, and Common Mistakes

A proforma invoice is the pre-sale document that sets the terms before anyone pays. Think of it as a formalized quote that looks almost exactly like a real invoice, but with “PROFORMA INVOICE” stamped on it. Buyers use it to approve costs, apply for letters of credit, or clear customs. You use it to lock in scope and avoid “but you said” disputes later.

Here’s exactly what to include, how to write one, and the mistakes that cost you time and money.

What to Include on Every Proforma Invoice

A proforma invoice needs to be specific enough that a buyer, a bank, or a customs officer can act on it. Cut the fluff. Include these fields:

• Document header – “PROFORMA INVOICE” in bold at the top. Do not call it “Quote” or “Estimate.”
• Seller and buyer details – Full legal names, physical addresses, phone, email, and tax ID or VAT number if applicable.
• Unique proforma number – Use a simple system like PF-2025-001. Never reuse invoice numbers.
• Date issued and validity period – “Valid until 30 days from date” is standard.
• Full description of goods or services – Be specific. “Consulting services for Q2 2025” is weak. “12 hours of paid media strategy consulting, including 2 revision rounds” is strong.
• Harmonized System (HS) code – For physical goods, include the 6-digit HS code. Buyers need this for customs.
• Country of origin – Where the goods are made. Required for international shipments.
• Incoterms 2020 – The delivery term (e.g., FOB, CIF, EXW). This determines who pays for shipping and insurance.
• Pricing in agreed currency – Show unit price, quantity, subtotal, and total. Use USD, EUR, or whatever you and the buyer agreed on.
• Payment terms – Deposit percentage, due dates, and accepted methods (bank transfer, credit card, etc.).
• Estimated shipping and handling fees – If you pass these costs to the buyer, list them separately.

How to Write a Proforma Invoice in 4 Steps

Step 1: Screen the buyer first. Before you send any document, check the buyer against denied party lists (for US exporters, the BIS Denied Persons List). If you skip this, you risk fines or losing export privileges.

Step 2: Build the proforma from your quote. Copy your quote into a template that matches your commercial invoice layout. Add the fields above. Double-check the HS code and Incoterm — these are common error points.

Step 3: Send it with a clear next step. Attach the proforma to an email that says: “Please review the attached proforma invoice. If everything looks correct, reply to confirm, and I’ll issue the commercial invoice for payment.” Do not ask for payment yet.

Step 4: Convert to commercial invoice after approval. Once the buyer confirms in writing (email counts), replace “PROFORMA INVOICE” with “COMMERCIAL INVOICE,” assign a real invoice number, and send the final bill. This is your trigger to ship or start work.

Common Mistakes That Cause Delays

Using a proforma when you need a binding quote. If the buyer needs a locked price for a contract, send a formal quotation or sales agreement. A proforma is an estimate — it’s not legally binding on its own.

Skipping the HS code or Incoterms. Without these, customs can hold your shipment for days. The buyer’s bank may also reject a letter of credit application. Always include both.

Leaving the validity period blank. If you don’t specify when the proforma expires, the buyer can come back three months later expecting the same price. Write “Valid for 30 days” directly on the document.

Treating it like a deposit invoice. A proforma is not a request for money. Do not include payment links or “Pay Now” buttons. That confuses buyers and creates accounting messes. The proforma is for approval — the commercial invoice is for payment.

Using vague descriptions. “Various parts” or “services rendered” will get rejected by customs and procurement teams. Write exactly what you’re selling, including quantity, unit type, and any serial numbers or model numbers.

Proforma vs. Commercial Invoice: The Difference That Matters

Send the proforma first. Get written approval. Then issue the commercial invoice. This two-step process prevents scope creep, payment disputes, and customs delays — especially in international trade.