In this article
Chase on a schedule you set when the invoice goes out, not one you invent when it goes overdue. Confirm before the due date, remind after it, then move from email to a phone call instead of sending the same message again. Consistency matters more than tone, and an arrangement to collect matters more than either.
Most advice on chasing out there is about wording. I'd argue the wording is the least important part.
The short version
- Decide the chasing schedule as you send the invoice, whether you need it or not. A schedule invented after the due date adds further delay.
- Confirm invoice receipt and approval before the due date. It prevents more delay than any reminder after it.
- Vary channels instead of repeating yourself. The third identical email is unlikely to be effective.
- 22% of businesses spend staff time chasing, averaging 86 hours a year each.
- There is no reliable answer on the best day or channel to send a reminder, so treat a confident one as a guess.
The short answer
A confirmation before the due date, a reminder just after it, a second reminder about a week later, then a call. Same wording each time, sent on a schedule that doesn't depend on anyone remembering.
Before you chase at all
There are three things you can do which might remove the need for chasing at all.
Check whether the invoice was ever seen by the right person. A significant share of "late" invoices haven't been refused by anybody, they're sitting with somebody who can't approve them, and that's a routing problem and not a chase. One question fixes it.
Check whether paying you was easy. If the only route to paying was a bank transfer somebody had to type in by hand, the cause of the delay may be how hard you made it and not a decision to hold off.
Check whether the client should have been on a mandate in the first place. Invoices set to collect automatically are paid 98.0% of the time, against 90.8% collected on demand (Adfin platform data, requests created in the seven months to the end of January 2026). Chasing well is worth much less than not needing to chase.
The sequence
| When | What | Why this step exists |
|---|---|---|
| A few days before the due date | Confirmation that the invoice is received, approved and scheduled | Catches routing and approval problems while there is still time |
| Day after the due date | Short reminder, same channel as the invoice | Establishes that you notice, without escalating |
| About a week later | Second reminder, naming the amount and the days overdue | Creates a record and a pattern |
| Two to three weeks over | A phone call to a named person | Changes the medium, which is the actual escalation |
| A month over | Formal notice, with the interest position stated | Moves from an admin matter to a commercial one |
| Beyond that | Letter before action, then a decision on the court or an agency | A decision, not a reflex |
Two rules hold the sequence together. Try not to send the same message a third time; change the medium instead. And set the whole schedule when the invoice goes out, because if you leave it, you'll be deciding whether to chase in the middle of a busy week, and you won't.
On larger invoices, start earlier. A big invoice often has to clear a sign-off you can't see from the outside, and the confirmation before the due date is where you find out about it while there's still time. A firmer reminder afterwards arrives once your customer's month has already closed.
What to say
The way to write these is short, factual, and with no apology for asking.
State the invoice number, the amount and the due date. Give the payment route in the message itself instead of pointing back at the original. Ask one specific question, because "please let us know" invites nothing while "can you confirm this is approved for payment on the 30th" invites an answer. And keep your tone constant all the way through the sequence, so the escalation comes from the medium and the facts and not from the adjectives.
What to leave out: a paragraph explaining the work again, a threat you're not going to act on, and any suggestion that you're sorry to be asking.
What the evidence cannot tell you
You'll find articles stating the best day of the week and the best hour to send a payment reminder, usually without a source. Treat them as invented.
Adfin can't publish a general answer either, and it's worth separating two questions that tend to get treated as one.
Whether a particular channel or hour works best across all businesses and all customers is a question about a population. No reliable public evidence settles it, our own reporting can't settle it, and any confident answer, ours included, is a guess.
Whether your particular client replies on WhatsApp and ignores email is a question about that client, and their own record answers it: the channels they've responded on, how quickly they paid afterwards, which invoices they queried. So you can act on a pattern in front of you even where there's no rule anybody can publish.
What is measurable is the shape of the problem. The median customer-initiated payment arrives 53 hours after the request and 42.9% arrive inside 24 hours (Adfin platform data). Payment clusters in the day or two after your request is read, and anything outside that window waits. That argues for making sure your request is seen early, and not for optimising the hour you send it.
When chasing isn't the right tool
When the same client is chased every month, what you've got is a collection arrangement problem. Move them onto a mandate.
When the invoice is disputed, reminders won't resolve it and they tend to harden positions. Answer the dispute.
When the amount is too small to justify your time, bear in mind that 86 hours a year is what doing this by hand across a ledger costs you. Some invoices are cheaper to automate, or to write off, than to pursue personally.
When the client can't pay as opposed to won't, an instalment arrangement collects more than escalation does, and you keep the client.
The sequence that runs without you
If the wording is the least important part, then what matters is that the sequence happens at all, and that's usually where it breaks. A schedule you set when the invoice went out still depends on you having attention spare in a week that has other plans, and the businesses affected by late payment already spend an average of 86 hours a year on this.
An agent removes the dependency, not the judgement. You set what it's allowed to do: the channels, how persistent to be, what goes out without review and what waits for you. It then works the sequence customer by customer and adapts to what each one responds to, sending from your own email domain instead of a generic one.
Two things stay with you. The call where somebody explains they're in difficulty, and the decision to escalate or wait. Those are the parts of this article worth your time, and they're easier to do well when you're not also remembering to send the day-eight reminder.
Common questions
How do I chase an unpaid invoice? Confirm before the due date that the invoice is approved, send a short reminder the day after it's due, a second about a week later, then change medium and call. Set the whole schedule when you send the invoice.
How often should I chase an unpaid invoice? Often enough that it reads as a pattern, and not so often that your client stops looking. Roughly weekly for the first month, changing medium instead of repeating the same message.
What is the best time of day to send a payment reminder? There is no reliable general answer, and the confident ones you'll find tend not to be sourced. There is often a per-client answer: that client's own history of replies and payments tells you more than any published best time.
Should I charge interest when I chase? You're entitled to interest on business debts, at base rate plus 8%, and the right applies whether or not your contract mentions it. Stating the position in a formal notice is usually more effective than adding small sums early.
How do I chase without damaging the relationship? Keep your tone constant and let the facts escalate instead of the language. Most of the awkwardness comes from irregular chasing that arrives as a surprise, so a predictable sequence is easier on the relationship than the occasional strongly-worded email.
What if the client keeps promising to pay? Convert the promise into a dated arrangement, ideally one that collects automatically. A promise with no collection mechanism behind it gets you the same conversation next month.
Sources
- Small Business Commissioner — late payments research (accurate as of August 2026)
Reviewed by the Adfin team. This article explains how to follow up unpaid invoices and is not legal advice. Last updated August 2026.
