Nobody starts a business because they enjoy asking people for money they have already earned.
And yet here you are, on a Sunday, working out who has not paid, drafting an email that took four attempts because the first three sounded either doormat or debt collector, and then not sending it because you do not want to annoy a customer you would quite like to work for again.
Meanwhile you are paying suppliers on time, because you always do, and the gap between those two facts is your overdraft.
Late payment is a cash problem a lot of owners find uncomfortable to deal with. Clear invoices and steady reminders help with a good part of it. They will not settle every dispute or fix a customer who has run out of money. Treat the timings in this guide as rough.
Before you start
You need a free Claude account. Claude is the AI assistant made by a company called Anthropic.
- On a laptop, go to claude.ai. On a phone, download the Claude app for iPhone or Android. Sign up with your email address.
- You will see a message box. Type or paste your request into it, then press the send button.
- Claude's reply appears underneath. When it does, that step is done.
Four things worth knowing before you paste anything in:
- Voice notes. To talk instead of type, tap the microphone on your phone's keyboard and speak. Your phone turns what you say into text, and you paste that text in.
- Leave out what you do not need. Skip bank details, and anything personal about a customer that the job does not need. If you would rather your chats were not used to train Anthropic's models, check the privacy settings in Claude.
- You check everything. What comes back is a draft. Read it against your own notes before it goes to anyone, and correct names, dates and prices. It does get things wrong.
- Limits. The free plan has usage limits. If you hit one, wait, or finish that one by hand.
Start with the uncomfortable audit
Before any of the writing, get the picture. You may find a surprise, often that you have been kind to your biggest customer for longer than you meant to be.
First, make sure the list is right. In your accounts software, check that recent receipts, part payments and credit notes are all entered, or you will chase money that has already come in.
Then use your accounts software's aged debtors or unpaid invoices report and export it. Software differs, so look for the report and its export option. Set the report date to today and choose the detailed version, with one line per invoice. You need the invoice number, customer, due date and the balance still owing. If you cannot export, type the same columns into a simple table. Replace customer names with labels such as Customer A if you prefer.
Attach the file with the attach button next to the message box, or paste the rows in. Done when you can see the file name above the box, or the rows in it, before you press send. Then ask:
Here is my list of unpaid invoices. Today's date is the one I give you here: [today's date]. Work out:
- The total outstanding, and how much of it is overdue rather than just unpaid
- How many days overdue each invoice is
- Whether the money owed is concentrated in one or two customers
- Which of the older invoices I should review first
Show your sums. If something is missing from the list, say so. Do not guess at reasons.
You are done when the total matches your accounts report and a couple of the overdue dates match the invoices when you check them by hand. Claude cannot see disputes, promises to pay or earlier reminders, so keep those in mind when you read the answer.
Two things might come out. One customer may account for most of what is late. Or many invoices may be sitting well past your stated terms, which means customers are paying later than agreed. Check both against the list before you believe them.
Check the invoice before you send it
Much late payment can be avoided before the invoice goes out. These are things to check:
- It went to the wrong person, or to an individual rather than to accounts
- It is missing a purchase order number, so their system rejects it
- The description does not match what their finance team was expecting to approve
- It arrived after their payment run, so it may wait for the next one
- Nobody told them it was coming
Ask about that first:
Here is an invoice I send regularly and here is who I send it to. What could slow this down inside a typical company's accounts payable process? What should I add or change?
Claude cannot know a particular customer's process. Confirm the recipient, any purchase order requirement, the approval deadline and how they pay directly with the customer, then update your own records.
Ask new customers these payment questions before you start work:
Draft me a short, friendly message to send to a new customer when I start work, asking the practical payment questions: who invoices should go to, whether they need a PO number, when their payment runs happen, and anything else their system needs. Make it sound like organised admin.
If they give you a processing cut-off, invoice in good time for it, under the terms you agreed. Do not hold an invoice back to hit a date, as that can delay payment.
A chase sequence, written once
Now the chasing itself. It eats your week when you write it fresh each time, agonising over tone. So write it once, as a sequence, and keep the rules for which email to send with it.
These are the rules this guide uses. Use your own terms, and take the due date from each invoice:
- Email 1: due within the next 7 days, or due today
- Email 2: from 1 to 13 days overdue
- Email 3: from 14 to 29 days overdue
- Email 4: 30 days or more overdue
Send each email once per invoice. An old invoice with no earlier chase does not have to start at email 1: send the email that matches its days overdue. If it has already had the email for its band, send nothing more until it moves into the next band. Check your chase log first (described under Making it a habit), including any reminders your accounts software has already sent. After email 4, do not send another email: phone them, then see the last section.
I want a set of four invoice chasing emails I can reuse, escalating in tone. My payment terms are [your agreed terms, for example 30 days].
- Due within the next 7 days, or due today. Friendly heads up, purely helpful.
- 1 to 13 days overdue. Assumes it has been overlooked, easy to fix.
- 14 to 29 days overdue. Firmer, asks for a payment date specifically.
- 30 days or more overdue. Formal, calm, and leaves the relationship intact if they pay.
British English, plain, no grovelling and no threats. Short enough to read on a phone. Leave labelled gaps for: recipient name, invoice number, amount still owing, due date, payment reference and my name.
Save the four in a note, or as four email drafts, and label them 1 to 4. Email 4 stays as it is for any customer the next section does not cover; the next section adds a separate 4B.
To use one, copy it into a new email, fill in every labelled gap, attach the right invoice and read it through once before it goes. Allow a little more time for replies and for keeping your records.
What the law gives you
The Late Payment of Commercial Debts legislation covers a debt owed to you by another business. It does not cover a household customer, so use email 4 for a household customer, never 4B. If your contract sets its own late payment interest, read it first, as it can affect what you can claim.
Where it applies, you can charge interest at eight per cent a year above the Bank of England base rate, plus a fixed sum on each overdue invoice: forty pounds on a debt under a thousand, seventy from a thousand up to £9,999.99, and a hundred on ten thousand or more. You can read the rules on GOV.UK.
Whether you charge it is your choice. A calm sentence noting the entitlement may help, but it is no guarantee anyone will pay sooner.
Use this only for a business customer, after you have read your contract and found no late payment terms of its own. If you are unsure, send email 4 instead.
Rewrite my 30 days or more overdue chase email to mention my entitlement to statutory interest and compensation under the Late Payment of Commercial Debts legislation. This customer is a business and my contract sets no late payment terms of its own. State it calmly as a fact. No threats. I want to keep this customer.
Read the result carefully before sending. The version that works sounds like someone who knows where they stand and would prefer not to make a fuss. Save it as email 4B, and keep email 4 as it is.
A worked example: this week's chasing list
An invented example. The firm and its customers are made up. All four customers are businesses.
Before. A small joinery firm in Wokingham, on thirty day terms, exports its unpaid invoices on Thursday 15 October. It follows the chase rules above and has no earlier chases recorded:
| Customer | Invoice | Amount | Due | Status | |---|---|---|---|---| | Hartley Lettings | 1042 | £2,350 | 2 September | 43 days overdue | | Brook Street Café | 1057 | £480 | 22 September | 23 days overdue | | R Patel Builders | 1061 | £1,120 | 6 October | 9 days overdue | | Oakfield School | 1066 | £3,900 | 17 October | due in 2 days |
After. The totals check out: £7,850 outstanding, of which £3,950 is overdue and £3,900 is not yet due. The owner works through the list from the oldest debt to the newest, because the longest overdue is the most urgent:
- Hartley Lettings, £2,350, 43 days overdue: email 4B, the formal one with the statutory wording. Hartley is a business, and the owner has checked the contract and found no interest terms of its own. On a debt of this size the fixed compensation is seventy pounds, plus interest.
- Brook Street Café, £480, 23 days overdue: email 3, asking for a payment date.
- R Patel Builders, £1,120, 9 days overdue: email 2, the "probably overlooked" note.
- Oakfield School, £3,900, due in 2 days: email 1, the friendly note before it falls due. It is the biggest sum, but it is not late, so it comes last. The owner also asks the school whether the Saturday due date means payment on the Friday before or the Monday after.
Here is the email 2 for R Patel Builders, filled in:
Hello Raj, a quick note on invoice 1061 for £1,120, which was due on 6 October. It may well have been overlooked. Could you let me know when it will be paid? The payment reference is 1061. Thanks, Sam
Then the owner sends all four, and notes each one in a simple chase log: invoice, date sent, which email, and the reply, if any.
Making it a habit
Pick fifteen minutes on the same day every week and put a repeating reminder in your calendar. Thursday is as good a day as any. Use the day that suits your customers' payment runs if they have told you. Export the debtors list, ask for what needs doing, send the emails, then write down what you sent:
Here is this week's unpaid invoices list, today's date, my saved emails 1 to 4 and 4B with the rules for when to use each, whether each customer is a business or a household, and my chase log. Tell me which invoices need chasing today and which email each one needs. List them oldest first. Leave out any invoice where the log shows a promised payment date that has not passed or an open dispute.
Keep the chase log simple: invoice, last email and date, their reply, and the next action. You are finished for the week when the emails are sent and the log is up to date.
Not every invoice fits the sequence:
- Already paid: check your bank, mark it paid and stop chasing.
- Part paid: chase the balance, and say what you received.
- Disputed: pause the sequence, correct the invoice if it is wrong, and talk to them directly.
- Promised a date: note it in the log and wait until the date passes.
- No reply: wait until the invoice reaches the next band before the next email, pick up the phone if you can, and after email 4 see the last section.
Spotting the customer who is always late
Doing this regularly shows you who is slow occasionally and who is slow every time.
That is a commercial decision, and it is yours. To see it plainly, export paid invoices as well as unpaid ones for the last twelve months, with their due dates and the dates they were paid. Include every customer, and keep unpaid invoices in, so the slow ones are not quietly dropped.
Here are the last twelve months of invoices for all my customers, paid and unpaid, with due dates and the dates paid. For each customer, work out how many days after the due date they usually pay. Count part payments by the date the balance cleared. Show the customers with the longest delays first, and tell me what is missing from the data.
Claude cannot know how much of your time a customer has taken, so keep a rough note of your own, and treat it as an estimate. Whether a customer is worth keeping depends on the margin on their jobs as well as how fast they pay, so look at both. With the figures in front of you, you can have a straight conversation about terms, deposits or whether to carry on.
When to take the next step
Done weekly, this can bring payment times closer to your terms, take the dread out of a Sunday job and leave you with a quarter of an hour on a weekday. Setting it up the first time takes longer than that.
You can do all of this yourself with an export and a saved set of emails. There are a few reasons you might go further later.
If the export and copying is where your time goes, look first at whether your accounts software already sends reminders. If it does not, connecting the two directly is a different kind of job to writing emails.
If someone else sends the reminders, agree which wording they can use and when they should ask you.
If an invoice has run on a long time and the customer has stopped replying, there is no magic number of days. Around ninety days overdue is a common rule of thumb, but you can act sooner. At that point more emails are unlikely to help. Gather the invoice, your terms, your chase log and every reply, and read the GOV.UK page above on debt recovery. Then speak to your accountant or take proper advice about formal recovery, mediation or writing it off.
Written by SmartGenie in Reading, Berkshire. If you would rather have this set up and working on your own systems, that is what the SmartStart Pack does.
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