How should I send an invoice by email?

Attach the invoice as a PDF, use a clear subject line with the invoice number and your business name, write a short message stating the amount and due date, include how to pay, and CC yourself for your records.

Should I send an invoice as PDF or Word?

Send a PDF. It looks the same on every device and can’t be accidentally edited, unlike a Word or Excel file. Invoicary exports a clean PDF you can attach directly.

What should the invoice email subject line be?

Include the word “Invoice”, the invoice number, and your business name — for example “Invoice INV-0001 from [Your Business]”. This gets it opened and makes it easy to find later.

How do I follow up on an unpaid invoice?

Send a polite reminder a day or two after the due date, a firmer one about a week later, and call if it’s still unpaid after two weeks. Re-attach the invoice each time and stay professional.

Should I CC myself when sending an invoice?

Yes. CC or BCC yourself so you have a timestamped copy of exactly what you sent and when — useful if there’s ever a dispute about whether the invoice was received.

How to Send an Invoice (Step by Step)

Once your invoice is ready, sending it well makes you look professional and helps you get paid on time. Here’s exactly how to send an invoice — the best way to send it, a copy-and-paste email template, and how to follow up if it goes unpaid.

Make & download your invoice free →

Before you send: a quick checklist

A unique invoice number and the correct issue and due dates
Your details and the client’s billing details are correct
Every line item, the tax, and the total are right
Payment terms and how to pay (bank details / link) are clearly stated
The file is a clean PDF — not an editable Word or Excel doc

The best way to send an invoice

For most freelancers and small businesses, the best way is email with the invoice attached as a PDF. It’s instant, gives you a written record, and the PDF looks identical on every device. There are three other options depending on your setup:

Email with a PDF attached — simplest and most common; works for any client
Accounting or invoicing software — sends the invoice and tracks when it’s viewed/paid
A client portal — some larger clients require you to upload invoices to their system
By post — rare now, but some government or enterprise clients still ask for a mailed copy

Invoice email subject line

A clear subject line gets your invoice opened and found later. Include the word “Invoice”, the number, and your business name. Good examples:

Invoice INV-0001 from [Your Business]
Invoice INV-0001 — [Project/Service] — due [date]
[Your Business]: Invoice INV-0001 for [Client Name]

Invoice email template (copy and paste)

Keep the message short and friendly — greet the client, say the invoice is attached, state the total and due date, give payment details, and thank them. Copy this and fill in the brackets: Subject: Invoice INV-0001 from [Your Business] Hi [Client Name], Please find attached invoice INV-0001 for [work/service], totalling [$amount]. It’s due by [due date]. You can pay by [bank transfer / card link / etc.] — details are on the invoice. If you have any questions, just reply to this email. Thanks for your business! [Your Name] [Your Business · phone · email] Attach the PDF and CC yourself so you have a copy of exactly what was sent.

How to follow up on an unpaid invoice

Most late payments are simple oversights, so a polite, well-timed reminder usually works. A good sequence is: a friendly nudge a couple of days after the due date, a firmer reminder about a week later, then a phone call. Reminder template: Subject: Reminder: Invoice INV-0001 now due Hi [Client Name], Just a friendly reminder that invoice INV-0001 for [$amount] was due on [due date] and is still showing as unpaid. I’ve attached it again for convenience. Could you let me know when I can expect payment? Happy to help if anything’s unclear. Thanks, [Your Name]

Day after due date: friendly reminder (template above)
~7 days overdue: firmer reminder, restate the amount and any late-fee terms
~14 days overdue: a short phone call is often the fastest fix
Keep every message polite and professional — the goal is to get paid and keep the client

How to get paid faster

Send the invoice immediately after the work is done — not days later
Use short, clear terms (e.g. Net 7 or Net 14 instead of Net 30)
Put payment instructions (bank details or a payment link) right on the invoice
Number invoices clearly and CC yourself so nothing gets lost
Send a polite reminder the moment an invoice goes overdue

FAQ

How should I send an invoice by email?: Attach the invoice as a PDF, use a clear subject line with the invoice number and your business name, write a short message stating the amount and due date, include how to pay, and CC yourself for your records.
Should I send an invoice as PDF or Word?: Send a PDF. It looks the same on every device and can’t be accidentally edited, unlike a Word or Excel file. Invoicary exports a clean PDF you can attach directly.
What should the invoice email subject line be?: Include the word “Invoice”, the invoice number, and your business name — for example “Invoice INV-0001 from [Your Business]”. This gets it opened and makes it easy to find later.
How do I follow up on an unpaid invoice?: Send a polite reminder a day or two after the due date, a firmer one about a week later, and call if it’s still unpaid after two weeks. Re-attach the invoice each time and stay professional.
Should I CC myself when sending an invoice?: Yes. CC or BCC yourself so you have a timestamped copy of exactly what you sent and when — useful if there’s ever a dispute about whether the invoice was received.