Why your customers don't pay on time (and the 4 things that fix it)

A mate of mine finished a 2-bed extension in March and was still £9,000 light in June. Not because the customer was a crook. The customer was a retired teacher who kept saying "of course, I'll sort it this week" and meant it every single time she said it. The invoice had gone out eleven days after the last skip left, on a Sunday night, as a photo of a handwritten page. No due date on it. No bank details on it either, so she'd have had to ring him to pay.

He blamed her for three months. It wasn't her.

Most late payment in the UK trades isn't fraud. It's friction. Somewhere between the last day on site and the money landing, there's a gap where the customer has to make a decision, and every day of that gap makes the decision easier to put off. This is what causes the gap, and the four things that close it.

Cause 1: the invoice arrived after the goodwill had cooled

The afternoon you pack up is the high point. The bathroom looks better than the customer expected. They've shown the neighbour. They feel like they got value.

That feeling is worth money, and it has a half-life of about 48 hours. By day four they're noticing the grout line near the cistern. By day ten the job is just a thing that happened, and your invoice is one of several bits of post they'll deal with at the weekend. It stops being "paying Adam for the lovely bathroom" and becomes "another bill".

There's also the practical side. An invoice that lands while the customer is still thinking about the job gets paid on their phone in ninety seconds. An invoice that lands ten days later gets filed in the pile with the water bill.

The fix: invoice the same day, from the van

Not that evening when you sit down. Not Saturday when you do the paperwork. Before you pull off the drive.

The invoice needs four things to be payable on the spot: the amount, the due date written as an actual date rather than "14 days", your bank details including the sort code, and a reference the customer can type. Miss any of those and you've built in a phone call, and the phone call is where the delay lives.

Cause 2: the payment terms were never actually agreed

If the first time a customer sees your payment terms is on the invoice, they haven't agreed to them. They've been told them, after the fact, at the point where they hold all the leverage because the work is already done.

Most of the time nothing bad happens. But when the customer is short that month, or when it's a main contractor whose own payment run goes out on the 25th, your 7-day term quietly becomes their 45-day term and there's nothing on paper that says otherwise.

The fix: terms on the quote, before a tool comes out the van

The quote is the document the customer accepts. That's where the payment terms belong, in a line they can't miss:

For a homeowner, that interest clause is the only thing that gives you the right to charge interest at all. For a business customer it's different: the Late Payment of Commercial Debts (Interest) Act 1998 gives you statutory interest at Bank of England base rate plus 8%, plus a fixed recovery cost of £40, £70 or £100 depending on the size of the debt, whether or not it's in your contract. Worth reading the full breakdown of the 1998 Act if you do any commercial work.

Cause 3: there's a snag they haven't told you about

This one catches people out because it doesn't look like a payment problem. It looks like silence.

The customer noticed the cupboard door catches, or the radiator in the back bedroom is slow to warm, or the tiler left a cut you wouldn't have accepted either. They don't want the confrontation, so they don't ring. They just don't pay, and they let the invoice sit there as a kind of unspoken message.

You read it as a cashflow problem. They mean it as a snag list.

The fix: a sign-off walk round on the last day

Ten minutes, the customer with you, both of you looking at the work. Anything they mention gets written down there and then, and either fixed before you go or dated for the following week. Then the sheet gets signed.

Two things happen. You catch the small stuff while the tools are still in the van, which costs you half an hour instead of a return visit. And the customer has told you in writing that the work is done, which removes the option of the silent snag later. A vague "I wasn't really happy with it" that appears for the first time three weeks after the invoice tends to evaporate the moment you ask for specifics in writing.

None of that stops a genuine defect being your responsibility. Under the Consumer Rights Act 2015 the work has to be carried out with reasonable care and skill, and a real snag is a real snag. Fix it fast, then reissue the balance with a fresh due date.

Cause 4: nothing happened when they missed the date

The due date passes. You think about it on the Tuesday, decide not to look keen, think about it again on the Thursday, and by the following week it feels awkward to bring up.

From the customer's side, the due date came and went and the world carried on exactly as before. That's the lesson they've learned, and they'll apply it to the next invoice too.

The fix: a chase schedule you run without thinking about it

Three dates, set the moment the invoice goes out:

• Day 1 overdue. Short, polite, administrative. "Just following up on invoice 214 for £2,400, which was due yesterday. Wanted to check there's no problem at your end." No edge on it at all.
• Day 14 overdue. Firmer, with the interest position stated and a specific new deadline seven days out.
• Day 30 overdue. Final notice before action, naming Money Claim Online for England and Wales, or the Simple Procedure for Scotland, with the total including interest and costs.

The wording for all three is in the late payment chase guide, along with what to do when the deadline on letter three passes.

The point of the schedule is that it takes the decision out of your hands. You're not deciding whether today is the day to be awkward. The calendar decided three weeks ago.

The worked example: what the four fixes are worth

Take a bathroom refit priced at £6,400 including VAT, with £2,950 of materials, run by Adam Wójcik trading as Wójcik Plumbing. Twelve days on site.

The old way

• Materials bought on the trade card on day one: £2,950 out of pocket
• Job finishes on the 12th. Invoice written up and sent on the 16th, four days later.
• Invoice says "payment within 30 days". Customer reads it as a target, not a deadline.
• Payment lands on day 58 after completion, after two awkward phone calls.
• The £2,950 sat on a credit card at 24.9% APR for 63 days: £127 in interest
• Plus roughly 3 hours of chasing, at a £45 hourly rate that's £135 of billable time gone

Total cost of that one late payment: about £262, on a job that made maybe £1,400. Nearly a fifth of the margin, on paperwork.

The fixed way

• Quote includes 25% deposit, 40% at first fix, 35% on completion within 7 days, with the interest clause.
• Deposit of £1,600 lands before day one. Materials mostly covered from the customer's money, not the card.
• £2,560 stage payment lands on day 6 at first fix.
• Sign-off walk round on day 12. Two snags caught and fixed on the spot.
• Balance of £2,240 invoiced from the van on day 12, due Monday the 21st, bank details and reference on it.
• Paid day 17. Card interest: £0. Chasing time: none.

Same customer. Same job. Same price. The difference is £262 kept and 41 days of cashflow recovered, and none of it required being tougher with anyone.

And if the balance had gone overdue anyway, the interest clause on the quote means a £2,240 balance sitting 30 days late accrues at 8% per annum, which is £0.49 a day, so £14.72 by day 30. Not a fortune. But it's a number on a letter, and a number on a letter changes how the customer reads the letter.

What NOT to do

1. Don't start with the money when you chase. Open with the invoice number and the date, not with how it's affecting you. The customer can argue with your circumstances. They can't argue with a date.
2. Don't drop the price to get paid faster. "Give me £2,000 today and we'll call it done" on a £2,400 balance teaches the customer that waiting saved them £400. It also tells them your original price had £400 of air in it.
3. Don't take the next job on for a customer who still owes you for the last one. It feels like keeping the relationship warm. What it actually does is give them a reason to hold the first balance as leverage on the second.
4. Don't chase by text and phone only. If it ever goes to Money Claim Online or the Simple Procedure, the court wants to see that you gave formal written notice and a chance to pay. A read receipt on a text isn't that. Escalate in writing every time, even if the relationship is friendly.
5. Don't threaten a step you're not going to take. If letter three says you'll file a claim on the 14th, file it on the 14th. One empty deadline and every deadline after it is a suggestion.

Where to start if you only do one thing

Same-day invoicing. It's the fix that needs no conversation with anyone, no new clause, no change to how you price.

It's also the one most people don't do, because writing an invoice at 4pm in the van is a faff when your invoice template lives on the laptop at home. That's the real blocker, and it's a logistics problem rather than a discipline problem. The TradeStash app is built for that thirty seconds on the drive: pick the job, check the figures, send. Paperwork done before you leave the driveway.

Get that one habit in and the other three get easier, because you're no longer starting every conversation from a week behind.