How to Send an Invoice to a Customer (Email Template Included)
Learn how to send an invoice to a customer step by step: what to attach, what to write in the email, when to send it and how to follow up. Free email template.

Sending an invoice sounds simple, but small details decide how fast you get paid. A clear email, a correct PDF and a visible due date can save you weeks of waiting.
The short version: create the invoice, check it, save it as a PDF, email it to the right person with a clear subject line, and note the due date so you can follow up.
How do you send an invoice in 5 steps?
- Create the invoice. Add your details, the customer's details, an invoice number, the date, the items, the tax and the total. If you need a refresher, read what to include on an invoice.
- Check every number. Wrong totals and missing VAT details cause delays and credit notes.
- Save it as a PDF. A PDF looks the same on every device and cannot be edited by accident.
- Email it to the person who pays. This is often the accounts team, not the person you worked with.
- Record the due date. Put it in your calendar and follow up if the invoice is still open.
Want to try it right away? Free Invoice Generator is free and needs no signup.
What should the invoice email say?
Keep it short and put the important facts in the first lines: the invoice number, the amount and the due date.
Subject: Invoice 2026-014 from Your Business, due 30 November
Hello Anna,
Please find attached invoice 2026-014 for £1,250.00 for the website design project. Payment is due by 30 November 2026.
Bank details are on the invoice. If you need a purchase order number or anything else added, let me know and I will send a corrected copy right away.
Thank you for your business.
Kind regards,
Your Name
When is the best time to send an invoice?
As soon as the work is delivered or the milestone is reached. Waiting makes it easier for the customer to delay, and the payment clock only starts when they receive the invoice. For long projects, agree stage payments in advance.
What can you attach or include?
| Item | Why it helps |
|---|---|
| Invoice as PDF | Clear, professional, easy to forward |
| Payment link or bank details | Makes paying a one-step action |
| Purchase order number | Many companies cannot pay without it |
| Contact for questions | Stops the invoice sitting unanswered |
How do you follow up?
Pick a rhythm and stick to it. A friendly reminder a few days before the due date, one on the due date, and a firmer note after it is overdue. See how to write a payment reminder email for ready-to-use wording, and invoice payment terms to set clear expectations from the start.
Common mistakes when sending invoices
- Sending to the wrong person or a generic inbox nobody reads.
- Leaving the due date out or hiding it at the bottom.
- Forgetting the invoice number in the email subject.
- Sending an editable file instead of a PDF.
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FAQ
Can I email an invoice as a PDF?
Yes. A PDF attached to an email is the most common way to send an invoice. Check that the rules for your country and customer do not require a specific e-invoice format.
Should I send the invoice before or after the work?
Usually after the work is delivered, or at agreed milestones. For large jobs you can invoice a deposit first.
How do I know the customer received it?
Ask for a short confirmation in your email, or request a read receipt. If you hear nothing, follow up before the due date.
Is this legal advice?
No. Invoice rules differ between countries. Check the requirements that apply to you.