How to Send an Invoice (+ Free Email Templates to Copy)

Sending an invoice takes two minutes. Sending it so it gets paid takes a little more thought: the right format, a clear email, and good timing.

This guide covers the ways you can send an invoice, what to write in the email, and how to follow up. It includes three email templates you can copy.

New to invoicing? Start with what an invoice is and what it should include.

Before you send: a 30-second check

An invoice with a mistake comes back to you, and the payment clock restarts. Before you hit send, confirm:

• The client's billing details and email address are right. Large companies often have a dedicated accounts payable address.
• The invoice number is unique and in sequence.
• The due date and payment terms are clear, for example Net 30 or due on receipt. Not sure which to use? Compare Net 30, Net 15 and due on receipt.
• Line items describe the work specifically enough that the client's approver recognizes it.
• Tax is calculated correctly, if you charge it.
• Payment instructions are on the invoice: how to pay and where.

The 5 ways to send an invoice

For most freelancers and small businesses, the answer is email with both a PDF and a link to view and pay online. The PDF satisfies record-keeping; the link removes friction from paying.

How to send an invoice by email

1. Create the invoice in a template, a free invoice generator or invoicing software.
2. Save it as a PDF. Never send an editable Word or Excel file: it looks unfinished and can be altered.
3. Name the file clearly, for example Invoice-1042-YourBusiness.pdf.
4. Write a short email with the invoice number in the subject line (templates below).
5. Attach the PDF and, if you have one, include the link to pay online.
6. Send it to the right person: whoever approves payment, not only the person you worked with.
7. Note the due date so you know when to follow up.

How to send an invoice with InvoiceCast

When your invoice is ready, click Finalize and Send. Finalizing freezes the invoice details and creates its online version, then gives you a choice of how to deliver it. You can reopen a finalized invoice to fix something until it's marked as sent.

1. Send it through InvoiceCast

InvoiceCast emails the invoice to your client for you: a clean email with the PDF attached and a link to the online invoice. If you accept online payments, your client can pay by card from that page.

• Tick Send me a copy to keep the sent email in your own inbox.
• Your client gets the email in the language you set for them (English or French).
• You can see whether the email was delivered and if the invoice page was opened, so you know whether "I never got it" is true.

This is the fastest option and the only one that tells you what happened after you clicked send.

2. Download the PDF and send it from your own email

Prefer your own email address and thread? Download the PDF and attach it to an email from Gmail, Outlook or any other provider. Use one of the templates below.

Tip: also paste the invoice's online link into your email. Your client gets the PDF for their records and a one-click way to view and pay.

3. Copy the link and share it anywhere

Copy the invoice link and paste it wherever your client actually reads messages: Slack, Teams, WhatsApp, a text or a project tool. The link opens the online invoice, with payment options if you've enabled them.

4. Open it in your email app

Choose Open in email app to start a pre-filled draft in your default email program, then review and send it from your own account.

5. Already delivered it another way? Mark it as sent

Handed a printed invoice to your client, or uploaded it to their procurement portal? Click Mark as sent so your invoice list and dashboard stay accurate, and the invoice moves on to tracking payment.

Coming soon: send from your own Gmail account

We're adding the option to connect your Gmail account and send invoices from your own address, directly from InvoiceCast. Your clients will see your email in their inbox, replies will come back to you, and you won't need to download and attach anything. This guide will be updated with the steps as soon as it's available.

Want to try the options above on your first invoice? The Free plan includes unlimited invoices and clients.

Invoice email templates you can copy

First invoice to a new client

Subject: Invoice #1042 from [Your Business], due [date]

Hi [Name],

Thank you for working with me on [project]. Please find invoice #1042 for [amount] attached. It's due on [date].

You can also view and pay it online here: [link]

If anything needs to go to someone else in your team, let me know who and I'll send it over.

Best, [Your name]

Regular or monthly invoice

Subject: Invoice #1043 – [Month] services – [Your Business]

Hi [Name],

Here's the invoice for [month]: #1043 for [amount], due [date]. PDF attached, or pay online here: [link]

Thanks as always, [Your name]

Billing the same client every month? Recurring invoices send on a schedule, so you don't have to remember.

Friendly reminder (a few days after the due date)

Subject: Reminder: invoice #1042 was due [date]

Hi [Name],

A quick reminder that invoice #1042 for [amount] was due on [date]. I've attached it again, and you can pay online here: [link]

If it's already on its way, thank you, and please ignore this note.

Best, [Your name]

When to send an invoice

• Right after the work is delivered. Every day you wait is a day added to when you get paid.
• On the schedule you agreed for retainers and monthly work, the same day each month.
• At milestones for larger projects, as agreed in your quote.
• On weekday mornings, if you have the choice: an invoice that arrives Friday evening sits under the weekend's email.

How to follow up on an invoice

1. On the due date, check whether payment has arrived.
2. A few days after, send the friendly reminder above.
3. After two weeks, call or message your contact directly and ask if anything is blocking payment: a missing PO number, the wrong approver, a question about a line item.
4. Keep everything in writing and keep your tone neutral. Most late payments are process problems, not refusals.

Clear payment terms on the invoice make every step of this easier.

FAQ

Should I send an invoice as a PDF or a link?

Both, if you can. The PDF gives your client a record to file; the link makes paying faster. InvoiceCast's emails include both.

What do I write in an email when sending an invoice?

Keep it short: the invoice number, amount, due date, how to pay, and a thank-you. Put the invoice number and due date in the subject line so it's easy to find later.

Can I send an invoice without software?

Yes. Make it in a template or a free generator, save it as a PDF and email it. Software becomes worth it once you're sending invoices regularly and want numbering, reminders and online payments handled for you.

How do I know if my client received my invoice?

With a plain email attachment, you usually can't. When you send through InvoiceCast, you can see whether the email was delivered and opened.

Make your next invoice in minutes, then send it the way your client prefers. Start free with InvoiceCast →

Last updated October 2026.