The email you send with a new invoice is easy to treat as an afterthought, yet it is the first thing the client reads and it sets up whether the invoice gets paid on time. A good invoice email is short, states the amount and due date up front, and makes paying obvious, so the invoice does not sit unopened in an inbox. This is the message that delivers a fresh invoice, not a reminder for a late one. Here is what to put in an invoice email, templates you can copy, and subject lines that get opened.
What to put in an invoice email
An invoice email should carry the essentials without burying them in text.
A clear subject line:: the invoice number, your name, and ideally the due date.
A brief thank-you:: a line acknowledging the work or the client.
The key facts:: the invoice number, the amount, and the due date, in the body, not only in the attachment.
How to pay:: the accepted methods, so the client can act immediately.
The invoice attached:: as a PDF, so it is professional and easy to file.
A short close:: an offer to answer questions, and your name and business.
Putting the amount and due date in the body matters, because many clients skim the email and never open the PDF. If the essentials are in the email itself, the client can approve or forward it to accounts payable without a second step.
Invoice email templates
Copy these, swap in your details, and keep them short.
Standard invoice email
Subject: Invoice #1042 from [Your Name], due [date]
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Hi [Name], thank you for [project or work]. Please find invoice #1042 for $[amount] attached, due [date]. You can pay by [methods]. Let me know if you have any questions, and thanks again. Best, [Your Name], [Business]
First-time client (a little more context)
Subject: Invoice #1042 for [project], due [date]
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Hi [Name], it was a pleasure working on [project]. Attached is invoice #1042 for $[amount], due within [terms] on [date]. Payment details are on the invoice; I accept [methods]. If you need a PO number added or route invoices differently, just let me know. Thanks, [Your Name]
With a deposit or milestone
Subject: Deposit invoice #1042 for [project]
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Hi [Name], thanks for confirming [project]. Attached is invoice #1042 for the [50%] deposit of $[amount], due [date], which I will schedule the work against once received. The balance of $[amount] will be invoiced on completion. Let me know if you have any questions. Best, [Your Name]
Whichever you use, keep it to a few lines and lead with the amount and due date, since a short, clear email is more likely to be acted on than a long one.
Subject lines that get opened
The subject line decides whether the email is opened today or buried. Make it specific.
Include the invoice number and the due date, for example "Invoice #1042 from [Your Name], due August 22," so the email is easy to find later and the deadline is visible before it is even opened. Avoid vague subjects like "Invoice" or "Payment," which are easy to skip. If the client uses purchase orders, adding the PO number to the subject helps their accounts payable match it quickly.
Send the invoice and email together
The email is only half of it; the invoice itself has to be clear and professional, with the same amount, due date, and payment methods you stated in the message.
Our free invoice generator builds a professional invoice PDF with all of that laid out, in minutes and with no signup, so what you attach matches what you wrote. For the invoice itself, the how to write an invoice for freelance work guide covers every field, and the how to send an invoice guide covers reaching the right person. The free tool handles a one-off send; FileCurrent goes further, emailing the invoice for you and, if it goes unpaid, sending the reminders automatically, which the invoice reminder email template covers for the follow-up stage.
Frequently asked questions
What should I write in an email when sending an invoice?
Keep it short: a clear subject line with the invoice number and due date, a brief thank-you, the amount and due date in the body, how to pay, the invoice attached as a PDF, and a short close with your name. Putting the key facts in the email itself, not just the attachment, is what gets it approved or forwarded quickly.
What is a good subject line for an invoice email?
A specific one that includes the invoice number and the due date, such as "Invoice #1042 from [Your Name], due August 22." It makes the email easy to find later and puts the deadline in view before the email is even opened. Avoid vague subjects like "Invoice" or "Payment," which are easy to overlook.
Should I attach the invoice as a PDF?
Yes. A PDF looks professional, cannot be edited in transit, and is easy for a client to file and forward to accounts payable. Still put the amount, due date, and payment methods in the email body as well, since many clients skim the message without opening the attachment, and you want the essentials visible either way.
What is the difference between an invoice email and a reminder email?
An invoice email delivers a new, current invoice and sets up payment. A reminder email chases an invoice that is due soon or already overdue, and its tone firms up as time passes. Use a friendly, straightforward invoice email when you first send the bill, and switch to a reminder sequence only if it is not paid on time.
How do I email an invoice to a client?
Build a clear invoice PDF, write a short email with a specific subject line, state the amount and due date and how to pay in the body, attach the PDF, and send it to the billing contact, not just your day-to-day contact. Asking who handles invoices, and whether they need a PO, avoids the delay of the email reaching the wrong person.
A clear invoice email gets your invoice opened, understood, and paid on time. FileCurrent builds the invoice, emails it for you, and chases it automatically if it goes unpaid, so sending an invoice is one step instead of three. $15/month or $129/year. 7-day free trial, no card required.