How to Send a Proforma Invoice by Email — Subject Lines, Body Text & Tips

A proforma invoice sent by email is the most common delivery method in international B2B trade. The email subject line and body text are read by the buyer's purchasing team, accounts payable, and sometimes their bank — so professionalism matters as much as the document itself.

Step 1 — Prepare the proforma invoice PDF

Always send a PDF, never a Word (.docx) or Excel (.xlsx) file, as the final proforma. PDF cannot be accidentally edited, and the layout is guaranteed to render identically on any device. Use our free online generator to create and download a PDF in under two minutes, or use the free template and export to PDF.

Step 2 — Name the file correctly

Name the PDF file clearly so it is easy for the buyer to find later:

• Good: PI-2026-0042-YourCompany.pdf
• Good: ProformaInvoice-BuyerName-Jul2026.pdf
• Avoid: invoice.pdf, document1.pdf, untitled.pdf

Step 3 — Write the email subject line

The subject line must be clear, professional, and scannable. The buyer's inbox likely receives dozens of supplier emails per day.

Recommended formats:

• Proforma Invoice #PI-2026-0042 — [Product Name] — [Your Company]
• Quotation / Proforma Invoice — [Product] — Valid until 03 Aug 2026
• Re: RFQ-[BuyerRef] — Proforma Invoice Attached

Step 4 — Write the email body

Keep it short and professional. The invoice speaks for itself — the email just introduces it.

Step 5 — Send the PDF as an email attachment or share a link

Two options:

• Email attachment — attach the PDF directly. Maximum file size for most corporate email systems is 10–25 MB; a proforma PDF is typically under 500 KB so this is not an issue.
• Share link — our free generator creates a unique short link (e.g. proformainvoices.com/i/abc123) you can paste into the email. The buyer clicks to view the proforma in their browser and downloads a PDF. Useful when you do not want to manage file attachments.

Step 6 — Follow up

If you have not received a response within 3 business days, send a short follow-up:

Common mistakes when sending a proforma invoice by email

• Sending the editable Word file instead of PDF
• Generic subject lines like "Invoice" or "Document"
• No validity date mentioned in the body — buyer does not know urgency
• Forgetting to mention the payment summary — buyer should not have to open the PDF to see the amount
• Not CC'ing your accounts department so they track it