Guide · Getting Paid

How to Write an Invoice Email
With Ready-to-Use Templates

5 min read · May 2026 · By InvoiceFlyer

Most freelancers spend time getting the invoice right and then fire off a two-word email: "Please find attached." That's a missed opportunity. The email you send with your invoice is the first thing the client sees — and a well-written one sets the tone, reinforces professionalism, and makes it easier for the right person to process the payment.

Here's exactly what your invoice email should contain, what to avoid, and ready-to-use templates for every situation.

What Every Invoice Email Needs

The One Rule

Keep it short. Your invoice email is not the place for lengthy project summaries or small talk. Aim for 5–7 sentences maximum. Respect their inbox.

Template 1 — Standard Invoice Email

Use this for most project invoices sent to existing or returning clients.

Template 2 — First Invoice to a New Client

When it's the first time you're invoicing someone, a slightly warmer tone helps establish the relationship.

Template 3 — Invoice for Ongoing / Retainer Work

For monthly retainer clients, keep it brief and consistent. They're expecting it.

Template 4 — Friendly Payment Reminder

Send this 5 days before the due date for clients who have a history of paying late.

Template 5 — Overdue Invoice Follow-Up

Direct and professional. Send this 1–3 days after the due date if payment hasn't arrived.


Common Invoice Email Mistakes to Avoid

A vague subject line

"Invoice attached" or "Please see attached" are the most common subject lines — and the worst. They're impossible to search for, easy to overlook, and tell the client nothing. Always include the invoice number, amount, and due date in the subject.

Apologising for sending the invoice

"Sorry to bother you" and "I hate to ask but…" are phrases that undermine you before the email even begins. You're not bothering anyone. You delivered work and you're requesting payment. That's a normal business transaction — treat it like one.

Burying the key details

If the client has to open the PDF to find out how much they owe and when it's due, you've added friction. Put the invoice number, total, and due date directly in the body of the email.

Sending at the wrong time

Emails sent on Friday afternoons or Monday mornings get buried. Tuesday through Thursday, between 9am and 2pm, consistently see higher open and response rates for business emails. It's a small thing, but it matters for time-sensitive payment requests.

Generate the Invoice First

Before you write the email, you need the invoice. InvoiceFlyer generates a professional PDF in seconds — describe your work, AI fills the details, export and send. Free, no signup.

✦ Generate Your Invoice Free