What to Do When a Client Doesn't Pay Your Invoice
A client hasn't paid your invoice. Here is what to send on day 1, day 7 and day 30, three emails to copy, and the interest and fees you may add.
Noman Mustafa Owner
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The due date has passed and the money is not there. A client not paying on time happens to everyone who bills clients.
Most of the time nobody is cheating you. The invoice went to the wrong person, or it is stuck waiting for an approval nobody told you about.
Here is the plan, day by day, with the exact words to send. There is also a section on the interest and fees you may be allowed to charge, with the figures.
How to chase an unpaid invoice, step by step
Six steps. Do them in this order, because the early ones solve most cases.
Check your own invoice before you chase anyone. Open the PDF you sent. Is there a real due date, your full bank details, and the client's purchase order number? If something is missing, fix it in the invoice generator and send a corrected copy. A lot of late invoices are late because of this.
Resend it with one short line. No anger, no apology. Attach the same PDF and ask them to confirm they have it. People lose emails, and a resend gives them an easy way out.
Talk to a human. Email is where chasing goes to die. Call, or message on WhatsApp if that is how you normally deal with them. Ask one question: has this been approved for payment, and if not, who approves it?
Send a firm reminder with a new date. Repeat the invoice number, the amount and the original due date. Then give a specific new deadline, like 26 November. Vague requests get vague answers.
Send a final notice. Say plainly that if payment is not received by the date, you will add late payment interest and pass it on for recovery. Keep it polite and keep a copy.
Pick your last option. A debt collector, a small claims case or writing it off. The right choice depends on the amount and whether the client still trades.
Step 1: a real due date and the client's PO number, on the invoice itself.
At every step, write down what you sent and when. If this ever reaches a court or a collector, that record is the thing that decides it.
The 60 day timeline
Here is what to send and when. Save this table, because the hardest part of chasing money is knowing when to move up a gear.
When | What you send | Tone |
|---|---|---|
3 days before the due date | A short heads-up with the PDF attached | Friendly, just a reminder |
Day 1 after the due date | Resend the invoice, ask them to confirm they have it | Neutral, assume it was missed |
Day 7 | Phone or message a person, then email what you agreed | Direct, asking a question |
Day 14 | Firm reminder with a new, specific deadline | Businesslike |
Day 30 | Final notice, mentioning interest and recovery | Formal, still polite |
Day 45 | Add the interest and send a fresh invoice for it | Factual |
Day 60 | Debt collector, small claims, or write it off | A decision, not a threat |
The same plan at a glance.
Two things make this work. You move on a schedule rather than when you are angry, and every message repeats the invoice number and the amount.
Also pause any further work for a client not paying by around day 14. Finishing more jobs for someone who has not paid for the last one is how small debts become big ones.
Three emails you can copy
Short beats clever. Each of these fits on a phone screen, which is where your client will read it.
The day 1 nudge
Subject: Invoice INV-2026-0001, due 5 November
Hi [Name],
Just checking this one reached you. Invoice INV-2026-0001 for $600 was due on 5 November. I have attached it again.
Could you confirm you have it, and let me know when it is due to go out?
Thanks, [Your name]
The day 14 reminder
Subject: Overdue: invoice INV-2026-0001, $600
Hi [Name],
Invoice INV-2026-0001 for $600 is now 14 days past its due date. The work was delivered on 20 October.
Please can you arrange payment by 26 November, or tell me what is holding it up? If it needs approval from someone else, I am happy to send it to them directly.
Thanks, [Your name]
The day 30 final notice
Subject: Final notice: invoice INV-2026-0001
Hi [Name],
Invoice INV-2026-0001 for $600 is now 30 days overdue, and I have had no reply to my last two emails.
If payment is not received by 12 December, I will add late payment interest and pass the debt on for recovery. I would much rather settle this between us.
Regards, [Your name]
If the client has gone completely quiet
Try a different channel and a different person. Message them on LinkedIn or WhatsApp, or email the accounts address instead of your usual contact. Many businesses have an accounts inbox that is read far more often than one person's email.
If you never had a written contract
You are not powerless. Emails agreeing the work, the brief, your delivery message and the invoice itself all count as evidence. Gather them into one PDF with Merge PDF before you speak to anyone else.
Does fixing or resending the invoice cost anything?
No. Resending the same PDF is free, and making a corrected one costs one credit.
The numbers. You get 20 credits a day without an account, and 50 with a free one. Making a PDF uses 1 credit. Downloading the same PDF again is free, so sending it four more times costs nothing.
No watermark. The free PDF is the same file a paying customer gets. A chasing email is a bad moment to send something with another company's name stamped across it.
Your data. Signed out, the invoice stays in your own browser. The PDF is deleted from the servers an hour later, automatically, and everything travels over HTTPS.
A credit note, not a quiet edit. If the invoice was wrong, do not just change it and resend. Raise a credit note that cancels it, then issue a corrected invoice. That is what an accountant or an auditor expects to see, and it protects you if the dispute grows.
One honest note. Convertavo makes invoices, it is not your accountant or your lawyer. Payment rules differ by country and they change. For a large debt, get proper advice where you live.
Pick Credit note from the Document menu to cancel a wrong invoice properly.
Can you charge interest on a late invoice?
In many places, yes, and the amounts are set by law rather than by you. The UK rules are the clearest published example, so here they are with the real figures. Check your own country's rules, because they differ.
The figures below are UK law. Rules differ by country, so check the rules where you and your client do business.
When a payment counts as late
If you agreed a payment date, it usually has to be within 30 days for public authorities and 60 days for business to business work. A longer period can be agreed, but it must be fair to both sides.
If no date was agreed, the law treats the payment as late 30 days after the customer gets the invoice, or after you delivered the work, whichever is later.
That second rule matters. People think a vague deal means no deadline. It does not.
How much interest
Statutory interest between businesses is 8% plus the Bank of England base rate. You cannot claim it if your contract already sets a different interest rate.
The government's own worked example: on a £1,000 debt with a base rate of 0.5%, the yearly interest is £85. That is 23p a day, so after 50 days you are owed £11.50 on top of the £1,000.
The fixed fee most people never claim
You can also charge a fixed sum for the cost of recovering the money, once per payment.
Amount owed | Fixed fee you can charge |
|---|---|
Up to £999.99 | £40 |
£1,000 to £9,999.99 | £70 |
£10,000 or more | £100 |
On a small invoice that fee is often worth more than the interest. Almost nobody claims it, because almost nobody knows it exists.
How to actually add it
Do not scribble it on the old invoice. Send a new one for the interest and the fee, with its own number and its own due date.
Mention this in your terms before you need it. A line like "late payment interest applies after 30 days" in the Terms box costs you nothing and changes how an invoice is treated.
One line in the Terms box, printed on every invoice you send.
Why your invoice is really sitting unpaid
Most of the time a client not paying is down to one of these nine, and none of them is fraud. Check this list before you assume the worst.
What is happening | Why | What to do |
|---|---|---|
"We never got it" | It went to one person who was away, or to spam | Resend to the accounts inbox as well as your contact |
It is stuck in approvals | Nobody told you a manager has to sign it off | Ask who approves it, then send it to them directly |
The purchase order number is missing | Many companies cannot pay without one | Ask for the PO number and reissue with it on the invoice |
Your bank details are not on it | Accounts will not chase you for them | Add full payment details and send a corrected PDF |
They paid less than the total | They deducted withholding tax | Show the withholding rate on the invoice so the figures match |
They dispute the amount | A discount or scope change was never written down | Send the emails that agreed it, then a credit note if they are right |
They pay on a fixed run | Some firms only pay suppliers twice a month | Ask for the payment run dates and invoice to fit them |
The due date is unclear | "Due on receipt" gets filed, not paid | Put a real date on every invoice from now on |
They have no money | The business is in trouble | Act early, since the first supplier to chase usually gets paid |
The fix for seven of these is the same. Open the invoice, correct the one missing detail, and send it again the same day.
Bank details go in Payment details and print on every PDF. The values here are examples.
Other free tools that help here
Merge PDF puts the contract, the emails and the invoice into one file before you send it to a collector or a court.
PDF to Excel pulls a supplier statement into rows, so you can see which invoices are still open.
Compress Image shrinks a logo that is over 2 MB when you are fixing the invoice.
Fix the invoice, then send it today
A client not paying is rarely a lost cause. Open the PDF and look for the three things that stop payment: a real due date, full bank details, and the client's PO number. If any are missing, rebuild it in the free Convertavo invoice generator and resend it the same day. Then put the day 7 reminder in your calendar before you close the laptop.
Sources
Late commercial payments: when a payment becomes late, GOV.UK, for the 30 and 60 day rules.
Interest on late commercial payments, GOV.UK, for 8% plus the Bank of England base rate and the worked example.
Claim debt recovery costs on late payments, GOV.UK, for the £40, £70 and £100 fixed sums.
Invoice Generator, Convertavo, read 22 October 2026, for credits, re-downloads, watermarks, credit notes, withholding tax and the privacy terms.
Frequently asked questions
How long should I wait before chasing an unpaid invoice?
One day. Send a short note the day after the due date, asking them to confirm they have the invoice. Waiting a week just moves you to the back of their payment queue.
Can I charge a late fee if I never mentioned one?
In the UK, statutory interest applies between businesses whether or not you wrote it down, unless your contract sets a different rate. Rules differ elsewhere, so check yours. It is still better to put a line in your terms first.
What if the client says they never received it?
Resend it the same day and copy their accounts address. Ask them to confirm receipt in writing. That reply is useful later, because it removes the main excuse.
Should I stop work when an invoice is overdue?
Usually yes, at around two weeks. Say it calmly, in one line, and offer to restart as soon as payment lands. Delivering more unpaid work makes the problem bigger.
Can I just edit the old invoice and send it again?
If it was never issued properly, yes. If it is a real financial record, raise a credit note and issue a corrected invoice instead. Auditors expect both documents to exist.
When is it worth going to small claims?
When the amount is worth the fee and the time, and the client is still trading. Many people find the final notice settles it, because the client realises you are keeping records.
Try it on your own file
Free, no signup, and your file is deleted an hour later.
Noman Mustafa — Founder of Convertavo I build the file tools on this site. Fifteen years of writing software, and most of my days now go into making PDF, image and OCR processing fast enough to run in a browser tab. I write here about what I learn breaking files apart.
