Should I send an invoice as a PDF or in the email body?

Both. Attach the PDF for their records and put the total, due date and payment link in the body so it can be acted on without opening anything.

When should I send an invoice?

As soon as the work is delivered or the milestone is met. Payment terms start from the issue date, so every day you delay sending is a day added to waiting.

Is it rude to chase an unpaid invoice?

No. A factual reminder on a named date is normal business practice, and most late payments are an oversight rather than a refusal.

How do I prove a client received my invoice?

Send it from software that records when the invoice page was opened. Email delivery alone does not prove it was read.

PaidSeal › Answers

How to Send an Invoice (Email, Link, and Getting Paid)

Updated 2026-10-22

How do I send an invoice?
Send an invoice to the client’s accounts-payable address, not just your contact, with the invoice number in the subject line and a payment link in the body. Attach a PDF for their records, state the due date in the first sentence, and keep the thread so reminders stay in context. Sending from invoicing software also records when the client opened it.

Send it to the right address

Many late payments are not disputes, they are misdeliveries. Ask once, at the start of the job: “Which address should invoices go to, and do you need a PO number on them?”

Copy your contact so somebody who cares about the work can chase it internally.

What to put in the email

Keep it to four lines. A subject line that can be searched, the amount, the due date, and the way to pay.

Subject: Invoice INV-0042 from [your business] — due 17 March
Body: one sentence naming the work, the total and the due date
A payment link, above the fold, not buried under a signature
The PDF attached, because finance teams file attachments

PDF, link, or both

Send both. The PDF is the record; the link is how you actually get paid. A link lets the client pay in the moment they read the email, which is the only moment you reliably have their attention.

A hosted invoice page has a second advantage: you can see that it was opened. “I never received it” stops being a possible answer.

Following up without souring the relationship

Reply in the same thread rather than starting a new one, and keep it factual:

Three days before due: a short note that it falls due on the date.
The day after: state it is now overdue and re-send the link.
Day 14: ask directly when it will be scheduled for payment.

PaidSeal sends these automatically on a schedule you set, stops the moment the invoice is paid, and records that the client viewed the page, so you are following a fact rather than a feeling.

Frequently asked questions

Should I send an invoice as a PDF or in the email body?: Both. Attach the PDF for their records and put the total, due date and payment link in the body so it can be acted on without opening anything.
When should I send an invoice?: As soon as the work is delivered or the milestone is met. Payment terms start from the issue date, so every day you delay sending is a day added to waiting.
Is it rude to chase an unpaid invoice?: No. A factual reminder on a named date is normal business practice, and most late payments are an oversight rather than a refusal.
How do I prove a client received my invoice?: Send it from software that records when the invoice page was opened. Email delivery alone does not prove it was read.

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