How to Email an Invoice

Last updated 26 August 2026 · By InvoiceSonic Team · 7 minute read

Quick answer

Attach the final invoice as a clearly named PDF. Put the invoice number, your business name and due date in the subject line. In the message, state what the invoice covers, the amount, due date and how to pay. Send it to the correct billing contact, keep a copy, and use the same email thread for any correction or reminder.

Invoice email template

Subject: Invoice INV-1042 from North Studio — due 14 September

Hi Jordan,

Thanks for working with us. Attached is invoice INV-1042 for the August design work.

Amount due: $1,250.00
Due date: 14 September 2026

Payment details are on the invoice. If your accounts team needs a PO number or another detail, please let me know.

Thanks,
Alex

Write a subject line that is easy to find

A useful pattern is Invoice [number] from [business] — due [date]. Add the project or PO number when the customer uses one. Avoid vague subjects such as “Document attached.”

Use a meaningful PDF filename too: Invoice-INV-1042-North-Studio.pdf.

Send it to the right recipient

For a business customer, ask whether invoices go to an accounts address, portal or named approver. Copy your project contact when appropriate. Before sending a first invoice or changed bank details, verify the destination and payment information carefully.

First invoices, corrections and reminders

First invoice: mention the project and offer to supply any onboarding or PO information. Correction: clearly identify what changed and follow the appropriate credit-note or replacement process for your records. Reminder: keep the original number, amount and PDF in the thread.

For overdue wording, use the payment reminder templates.

Frequently asked questions

What should I say when attaching an invoice?

State what the invoice covers, its number, amount and due date, then point to the payment instructions and invite the customer to flag missing approval information.

Should I attach an invoice as PDF or Word?

Send the finished invoice as a PDF so its layout remains stable. Keep your editable source privately rather than sending it to the customer.

Should I put bank details in the email?

They can remain on the invoice. If you repeat them in email, ensure both copies match. Treat any changed payment details as sensitive and verify them through a trusted channel.

How do I resend an invoice?

Use the original thread where possible, reattach the same PDF, state that you are resending it, and confirm the invoice number, amount and due date.

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