To follow up on an unpaid invoice, first check that the invoice was sent correctly and not already paid, then send a short, friendly reminder on or just after the due date. If there's no reply, follow up on a fixed schedule with a gradually firmer tone, switch to a phone call after two unanswered emails, and send a clear final notice before taking any formal step. Start gently: an unpaid invoice is often forgotten, misplaced or waiting for approval rather than refused.
In short
- Check your records before you chase.
- First reminder: friendly, specific, easy to act on.
- Follow a schedule, not your mood; escalate one step at a time.
- Change channel when emails go unanswered.
- Offer a plan if the client is struggling.
- Final notice only with consequences you can actually apply.
1. Check before you chase
- Was the invoice sent, and to the right person? Many companies route invoices to a billing or accounts payable address rather than your project contact.
- Are the amount, due date and payment details correct?
- Has a payment already arrived that you haven't matched yet?
- Did you agree payment terms in writing, such as "due within 14 days"?
2. Send a friendly first reminder
Send it on the due date or within a few days after it. Mention the invoice number, amount and due date, include a payment link or bank details, and invite a reply if something is wrong. Assume good faith — the goal of the first message is to make paying the easiest next step.
"Hi Alex, just a quick reminder that invoice 1042 for $1,250 was due on 15 October. You can pay here: [link]. If you've already sent it, thank you — please ignore this note."
3. Follow up on a schedule
Decide the sequence in advance so you aren't drafting a new message each time you remember:
| When | Tone | What to say |
|---|---|---|
| Due date | Neutral | The invoice is due today; here is the link. |
| 3–7 days late | Friendly | It may have slipped through; here is the link again. |
| 10–14 days late | Direct | It is now two weeks overdue; please pay by a specific date or tell me what's holding it up. |
| About 30 days late | Formal | Final reminder with a deadline and the next step you will take. |
Copy-ready wording for every stage is in the payment reminder email templates; timing is covered in when to send payment reminders.
4. Getting the tone right
- Be specific, not emotional. Amounts, dates and references keep the message factual.
- Ask one thing. "Could you pay by Friday?" is clearer than several questions.
- Avoid blame. "Our records show the invoice is still open" works better than "You haven't paid".
- Escalate gradually. Change one thing at a time — a firmer subject line, then a deadline, then a consequence.
5. Change the channel
If two emails go unanswered, the message probably isn't being read. Call, send a short text if that's how you normally communicate (examples) or write to a different contact, such as the person who approved the work.
6. Offer a way forward
If your client is struggling, a realistic plan gets you paid more often than pressure does. Offer instalments or a new date, and confirm the agreement in writing.
7. Send a final notice before formal steps
State the overdue amount, a specific deadline and what happens next — for example pausing further work, or applying late fees if your contract allows them. Only mention consequences you are prepared and entitled to apply. For formal recovery or legal action, speak to an accountant or lawyer about the rules where you and your client are based.
8. Keep a record
Note what you sent, when and how the client replied. A clear history makes later conversations and any formal step much easier.
Scenarios
- Freelancer, single client project: keep it personal — a short email on the due date, a second one a week later, then a call. Pause new work for that client if the invoice reaches 30 days.
- Agency with many clients: agree who owns follow-ups, use the same schedule for every client and write to the billing contact as well as the project lead.
- Small business with regular customers: a reminder a few days before the due date often does most of the work; customers who pay every month rarely need more than one nudge.
Mistakes to avoid
Waiting weeks before the first reminder, sending angry or sarcastic messages, reminding someone who has already paid, sending many messages in a short time, and leaving out the amount, reference or how to pay.
Where automation fits
Steps 2 and 3 are the ones most often forgotten and the easiest to automate. With RemindCash invoice reminders, you set the schedule once, approve the wording, and reminders go out on time and stop when the invoice is paid. The personal steps — a call, a payment plan, a final decision — stay with you. To prevent late payments in the first place, read how to reduce late payments.