Yes, small unpaid invoices are usually worth chasing, as long as the chasing costs you next to nothing. Two rounds of chasing by hand on an £18 invoice can cost more than the invoice is worth, while an automated reminder costs almost nothing to send. Automate the reminders, move regular customers onto automatic payment and set a written point at which you write off whatever's left.
In this article
The short version
- Chasing by hand takes the same time whatever the invoice is worth.
- Most of the cost of chasing is your own time.
- Chase by hand only when the invoice is worth more than that time.
- Automated reminders, payment links and direct debit cut the chasing.
- Set a written point for writing off what's left.
What it costs to chase a small invoice
Most of the cost of chasing is your time, not the reminder. Say you value an hour of your own time at £48. Finding the invoice, checking it hasn't been paid, writing a polite email and noting the reply takes around 20 minutes, so each manual chase costs you about £16. Two rounds on an £18 invoice and you've spent £32 to recover £18.
Government research published in July 2025 found that businesses affected by late payment spend an average of 86 hours a year chasing it. If a lot of your invoices are small, a good share of those hours can go on amounts that barely cover the time spent.
Ignoring them has a price as well. Let three £18 invoices slip each month and you've lost £648 by the end of the year.
A rule for deciding which ones to chase by hand
A workable rule is to chase by hand only when the invoice is worth clearly more than the time you'd spend on it, and let automated reminders cover everything below that line. Using the £16 a round from above, and assuming a customer needs two manual chases:
| Unpaid invoice | Cost of two manual chases | Left after chasing |
|---|---|---|
| £18 | £32 | minus £14 |
| £45 | £32 | £13 |
| £137 | £32 | £105 |
| £1,140 | £32 | £1,108 |
Your own line will depend on your time and your customers. Work it out once, write it down and apply it to every customer the same way, so a small invoice isn't chased one month and quietly dropped the next.
A small invoice from a regular customer adds up, because £18 billed every fortnight comes to £468 a year, and a customer who learns they can skip the odd payment may start skipping more. A long-standing client who's simply forgotten may also deserve a quick personal note, whatever the amount.
How to get small invoices paid without chasing by hand
Once reminders send themselves, the sums above look very different, because one more reminder costs close to nothing. Adfin's Essential credit control, free under fair use, sends unlimited reminders by email, SMS and WhatsApp and syncs with Xero or QuickBooks, so an £18 invoice gets the same follow-up as a £1,140 one. If you'd rather not set the timing yourself, Adfin's collection agents, part of the paid Enhanced plan, choose the timing, channel and tone of each reminder within rules you approve.
You can also cut the number of invoices that need chasing at all:
- Put a payment link in every invoice and every reminder, so paying takes a minute on a phone.
- Move regular small customers onto direct debit or a card on file, so payment is taken on the due date without anyone remembering to pay.
- Send one statement to a customer with several small invoices open, so they can clear the lot in one payment.
With Adfin, a direct debit collects each invoice's own amount on its due date under one mandate, and your customer gets notice of the amount and date at least three working days ahead. A card on file is charged automatically for future invoices, with the customer told one business day before.
When to write a small invoice off
Some small debts won't come in however you chase them. A customer who's closed down, or who hasn't replied after several reminders over a couple of months, is unlikely to pay an £18 bill. Set the point in advance, for example three automated reminders and one phone call over 60 days, after which you stop and write the invoice off. Your accountant can tell you how to record it.
If the customer still buys from you, you can ask for payment before the next job, or ask them to set up a direct debit so the next small invoice is collected on its due date.
Common questions
Is it worth chasing an invoice under £100? Usually yes, if the reminders are automated, because each extra reminder costs almost nothing to send. Chasing by hand is harder to justify once the time you spend is worth more than the invoice.
How much does it cost to chase an unpaid invoice? It depends mostly on whose time it takes. Multiply the minutes each chase takes by what that time is worth, then by the number of rounds a customer usually needs.
Should I write off small unpaid invoices? Write them off once they've passed a point you've agreed in advance, such as a set number of reminders over a set period. A written threshold stops small debts sitting on the books for months with nobody deciding.
How do I stop small invoices going unpaid in the first place? Put a payment link in every invoice so paying is quick. For regular customers, a direct debit or a card on file takes payment on the due date without any action from them.
Can I put small regular customers on direct debit? Yes. A direct debit can collect a different amount each time under one mandate, provided the customer is told the amount and date in advance.
Is a statement better than chasing each small invoice separately? For a customer with several small invoices open, it often is. One statement with a single total is easier to act on than a string of separate reminders, and some systems let the customer pay it in one go.
Sources
- Department for Business and Trade and Office of the Small Business Commissioner - Late Payments Research: estimating the total economic cost of late payments and their impact on the UK economy (accurate as of October 2026) https://assets.publishing.service.gov.uk/media/688a089a6478525675738ff9/late_payments_research_impact_on_uk_economy.pdf
- Office of the Small Business Commissioner - Late Payments Research (accurate as of October 2026) https://www.smallbusinesscommissioner.gov.uk/?p=64916
- Adfin - Credit control (accurate as of October 2026) https://www.adfin.com/credit-control
