Set the chasing schedule when you send the invoice: a check a few days before the due date, a short reminder the day after, a second reminder about a week later, a phone call at two to three weeks and a formal notice at around a month. Each step changes the channel or the formality while the tone stays the same, and every message includes a way to pay.
In this article
The short version
- Set the chasing schedule when you send the invoice, not when it goes overdue.
- Check a few days before the due date that the invoice is approved.
- Remind the day after, again a week later, call at two to three weeks, then send a formal notice.
- Keep the tone the same and put a payment link in every message.
- If the same customer is late every month, move them to direct debit.
Before the due date
Often the most useful message you'll send goes out before the invoice is late. A short note a few days ahead, asking whether the invoice has reached the right person and is approved for payment, catches the problems behind a lot of late payment: an invoice sitting in a shared inbox, a missing purchase order number, a second signature nobody mentioned.
Two other things help before you chase at all. Put a payment link in the invoice email, so your customer can pay by card or bank in a minute without typing in your bank details. And check the due date itself. In Adfin's payment data, on-time payments bunch up on the due date, and invoices falling due on a Saturday or Sunday were paid on time less often than weekday ones. An invoice whose due date has already passed by the time it's sent is late on arrival, so it's worth checking your templates aren't doing that.
The sequence, step by step
| When | What to send | Why |
|---|---|---|
| 3 to 5 days before the due date | A check that it's received and approved | Catches routing and approval problems while there's time |
| The day after the due date | A short reminder, in the same channel as the invoice | Shows you've noticed, without escalating |
| About a week later | A second reminder, with the amount and days overdue | Asks for a payment date and creates a record |
| Two to three weeks overdue | A phone call to a named person | Changes the medium and gets a date |
| About a month overdue | A formal notice with a deadline and your interest position | Moves it from admin to a commercial matter |
| After that | A letter before action, then a decision | Arrangement, agency, small claim or write-off |
The exact days matter less than writing them down before the invoice goes out. If you plan to decide once it's overdue, the decision tends to slide until the debt is older and harder to collect.
Try not to send the same email a third time. A phone call after two emails tells your customer the matter has moved on, and it does that more clearly than firmer wording would.
On larger invoices, send the pre-due check a little earlier. A big invoice is more likely to need a sign-off you can't see from outside, and finding out a week before the due date leaves time to sort it.
What to put in each reminder
Keep each one short: the invoice number, the amount, the due date, one specific question and the payment link. "Can you confirm this is approved for payment on the 30th?" gets an answer, where "please let us know" usually doesn't. Leave out apologies, a re-explanation of the work and any threat you won't carry out.
Keep your tone level from the first reminder to the last, and let the facts and the channel do the escalating. In Adfin's data, almost half of late payments arrived within a week of the due date, which suggests a lot of late payment is admin running behind rather than a refusal to pay. Your first reminders are likely to land best when they read as routine.
When the sequence isn't enough
On the call, you're listening for which of three situations you're in. If the invoice is disputed, more reminders tend to harden positions, so deal with the query and restart the clock on the agreed amount. If your customer can't pay right now, offer an instalment plan, because you'll often recover more that way than by escalating. If they simply haven't prioritised you, agree a specific date and follow up on that date.
If the deadline in your formal notice passes, choose your next step: a letter before action, then a payment arrangement, a collection agency or a claim through the small claims track. On business debts you can add statutory interest at 8% above the Bank of England base rate, plus fixed compensation of £40 to £100 per invoice. And where pursuing a small debt would cost more than it's worth, writing it off is a reasonable end to the process.
If you're chasing the same customer every month, look at how they pay. A direct debit collected on the due date removes the chase altogether.
Most of these steps are routine messages that don't need your judgement. Adfin can run it for you: each reminder goes out at the step you've chosen, by email, text or WhatsApp, with a link to pay and from your own email address. Its Customer Agents can adjust the timing and channel for each customer and set up instalment plans, all within rules you approve, and you can pause them for anyone you're in talks with. The phone calls and the decisions stay with you.
Common questions
How soon should I chase an unpaid invoice? Send a short reminder the day after the due date. A check a few days before it's due tends to catch more problems than a reminder sent afterwards.
How many reminders should I send before calling? Two written reminders is usually enough. After that, a phone call to a named person tends to get further than a third email.
What should a payment reminder say? The invoice number, amount and due date, one specific question such as when it'll be paid, and a link to pay. Keep the tone the same in every message.
Should I charge interest when chasing a business customer? You're entitled to statutory interest and fixed compensation on late business invoices even if your contract doesn't mention them. Many businesses state the position in the formal notice at around a month overdue.
What if the customer disputes the invoice? Pause reminders on the disputed part, resolve the query and ask for any undisputed amount in the meantime.
When should I stop chasing? When the cost of pursuing it, in fees and your own time, is likely to be more than you'd get back. At that point, writing it off is usually the better use of your time.
Sources
- GOV.UK - Late commercial payments: charging interest and debt recovery (accurate as of October 2026) https://www.gov.uk/late-commercial-payments-interest-debt-recovery
- Bank of England - The interest rate (Bank Rate) (accurate as of October 2026) https://www.bankofengland.co.uk/monetary-policy/the-interest-rate-bank-rate
- GOV.UK - Make a court claim for money (accurate as of October 2026) https://www.gov.uk/make-court-claim-for-money
- Adfin - Credit control (accurate as of October 2026) https://www.adfin.com/credit-control
