How to Send an Invoice by Email (Templates, Subject Lines & Etiquette)
The right email gets your invoice opened, approved, and paid. Learn subject lines, body copy, attachments, and follow-up timing that finance teams respect.
Knowing how to send an invoice by email correctly can shave days off payment time. AP teams process hundreds of messages—yours needs to be scannable in five seconds.
Best Subject Lines for Invoice Emails
- Invoice #[NUMBER] from [Your Company] – Due [DATE]
- [Your Company] Invoice #[NUMBER] – [AMOUNT] Due [DATE]
- Invoice for [Project Name] – #[NUMBER]
Put the invoice number first—finance teams search by number, not by your name.
Invoice Email Template (Copy & Paste)
Subject: Invoice #INV-2026-042 from [Company] – $2,400 Due May 30
Hi [First name],
Please find attached invoice #INV-2026-042 for [brief description].
- Amount due: $2,400.00
- Due date: May 30, 2026
- Payment: Bank transfer details on invoice (or pay link)
Let me know if you need a W-9, PO reference, or vendor setup form.
Thank you for your business!
[Your name]
[Company]
[Phone]
Attachments and File Names
- Attach PDF (not editable Word)
- Name file: Invoice-INV-2026-042-CompanyName.pdf
- Keep body text short; details live in the PDF
Who to Email
For corporate clients, ask: "Who handles AP?" Copy accounts@ or ap@ when given. For small clients, billing contact is fine.
Timing Matters
Send invoices Tuesday–Thursday mornings in the client's time zone. Avoid Friday afternoons and Monday inbox floods.
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Professional templates
After You Hit Send
Mark the invoice sent in CrispInvoice. Schedule a reminder before the due date. If no read receipt, assume it arrived and follow up politely if unpaid.
Common Email Mistakes
- Pasting invoice details only in email (no PDF)
- Missing due date in subject and body
- Sending to the wrong stakeholder
- Forgetting tax or PO number finance needs
Professional email + professional PDF = faster approval. Generate both in minutes with CrispInvoice.