The fastest way to send an invoice is as a PDF attached to a short email, sent to the person who pays invoices, on the day the work is delivered. Put the invoice number, your business name and the due date in the subject line, and say in one sentence what the invoice is for, how much it is and when it is due.
Most late payments are not refusals. They are invoices that went to the wrong person, arrived without a purchase order number, or sank in an inbox. Sending well avoids all three.
When to send it
Send the invoice as soon as you are entitled to: on delivery, at the milestone, or on the date your agreement sets. Every day you wait is a day added to the payment.
- One-off jobs: on completion, ideally the same day.
- Projects: at each milestone or stage set out in your contract, plus a deposit invoice at the start if you take one.
- Recurring work: on the same day each week or month, so the client can expect it.
- Retainers: at the start of the period, if the retainer is paid in advance.
Who to send it to
Ask, before the work starts, who handles invoices and where they should go. In a small business it may be the owner; in a larger one, an accounts payable address such as ap@ or invoices@. Send it there, and copy the person you worked with so they can approve it.
At the same time, ask whether they need a purchase order (PO) number on the invoice, and whether they need any forms from you first, such as a W-9 in the US or supplier registration. A missing PO is one of the most common reasons an invoice is returned unpaid.
Sending it, step by step
- Check the invoice. Client name and address, PO number, dates, each line, the total and your payment details. An error found by the client restarts the clock.
- Save it as a PDF. Name the file so it is obvious: Invoice-INV-0042-Harbor-Pine-Bakery.pdf. See how to create an invoice PDF.
- Write the subject line. Invoice INV-0042 from Marlow Studio — due November 30.
- Write a short email. One sentence on what it is for, the amount and the due date, and a line inviting questions. The example below can be copied.
- Attach the PDF and send it to the accounts contact, copying your client contact.
- Record that you sent it. Note the date and the due date in your own records, so you know when to follow up.
An email you can copy
Keep it this short. The invoice holds the details; the email only has to get it opened and filed.
Attachment or link?
Attach a PDF unless the client asks otherwise. A PDF can be saved, forwarded and filed with their records, and it opens on any device. Payment links are helpful alongside it, especially for card payments, but a link alone depends on a service the client may not be able to open later.
Some large clients ask suppliers to upload invoices to a portal instead of emailing them. If so, follow their process exactly; invoices sent anywhere else are usually ignored.
Sending by post
Some clients, often public bodies, still prefer invoices by mail. Print the invoice on plain paper, sign it if they ask, and keep a copy of what you sent and when. Allow for postage time when you set the due date.
Following up on a late invoice
Most late invoices are paid after a single polite reminder. A sequence that works:
| When | What to send |
|---|---|
| A few days before the due date | Optional: a friendly note that the invoice is due on Friday |
| The day after the due date | A short reminder with the invoice attached again |
| One to two weeks late | A firmer email asking when payment will be made |
| About a month late | A phone call, then a final written notice stating the next step |
A reminder you can copy:
Stay factual and polite; there is usually a simple reason. If you agreed late fees in your contract, mention them only from the second reminder on. How to invoice a client covers setting terms so this is rarely needed.
Keeping a record
Keep a copy of every invoice you send, with the date sent and the date paid. You will need them for your accounts and your tax return. Folio keeps every invoice in your browser’s list and can download a backup file of them all; keep that backup somewhere safe.