How to Chase an Unpaid Invoice

How to chase an unpaid invoice: step by step

1. 1

   Day 1 after due date: a short, friendly nudge

   Assume it was missed. Reattach the invoice, restate the amount and the due date, and ask whether it reached the right person. Keep it to three sentences and do not apologise for asking.

2. 2

   Day 7: confirm it is in the system

   Ask a specific question rather than repeating the request: has the invoice been entered for payment, and is there a payment run date? This surfaces missing purchase order numbers and wrong billing contacts, which cause most delays.

3. 3

   Day 14: escalate to accounts payable

   Contact the finance or accounts payable address directly and copy your usual contact. State the invoice number, amount, original due date and how many days overdue it is. Keep the tone factual.

4. 4

   Day 30: formal notice

   Send a clearly labelled final reminder stating the amount outstanding, referencing the agreed payment terms and any previously agreed late payment interest, and giving a specific deadline. Say what happens next if the deadline passes.

5. 5

   Day 45+: escalate externally

   Depending on the amount, options are a formal letter before action, a debt recovery service, or a small claims process. Weigh the cost and time against the sum owed before starting.

Start before it is late

The cheapest chase is the one you never have to send. A short message a few days before the due date, framed as a courtesy rather than a demand, catches most administrative problems while there is still time to fix them.

Something as simple as "Just a heads up that invoice INV-042 is due on Friday. Let me know if you need anything from me to get it processed" will surface a missing purchase order number or a wrong billing address before it becomes an overdue account.

The first reminder

Keep it short, warm and specific. Do not open with an apology, and do not explain why you need the money. The invoice is due, that is reason enough.

Hi {name}, hope you are well. Invoice INV-042 for $1,200 was due on 5 September and I have not seen it come through yet. I have attached it again in case it got lost. Could you let me know if it has been received? Thanks.

Why most invoices are actually late

Before assuming bad faith, rule out the ordinary explanations. In practice the great majority of late payments come down to something procedural.

• The invoice went to your day-to-day contact, who never forwarded it to finance
• The client requires a purchase order number and the invoice does not have one
• The billing entity or address on the invoice does not match their records
• The invoice arrived after their monthly cut-off and rolled into the next cycle
• It went to spam, or to an individual who has since left
• Bank details were missing, unclear, or in a format their system rejected

Escalating without burning the relationship

The tonal shift from reminder to formal notice should be gradual and impersonal. Each message gets slightly shorter, slightly more factual, and slightly more explicit about consequences. What you are avoiding is the jump from silence straight to anger, which is what happens when you leave it three weeks and then write while frustrated.

A useful discipline is to decide the schedule in advance and follow it regardless of how you feel on the day. When chasing is a process rather than a decision, it stops being uncomfortable.

Move the conversation to the phone at around the two week mark if you can. A two minute call to accounts payable frequently resolves what four emails have not.

Stopping work

Pausing delivery is the strongest leverage most small suppliers have, and it is entirely reasonable when an account is significantly overdue. It only works cleanly if you flagged it in advance, both in your original terms and in the escalation messages, rather than springing it as a surprise.

Where the work is ongoing, be specific and neutral: "As invoice INV-042 is now 30 days overdue, I will need to pause work on the current phase until the account is settled." Then actually pause. A threat you do not follow through on removes the leverage entirely.

When to escalate formally

If a genuinely uncooperative client has ignored a formal notice, the practical options are a letter before action, a commercial debt recovery service, or a small claims process. Which is proportionate depends heavily on the amount and on where both parties are based.

Be realistic about economics. Recovery services typically take a percentage, and court processes cost time even when fees are modest. For small sums, a firm final notice recovers more in practice than a process that costs more than the debt.

Whatever route you take, having the paper trail helps enormously: the accepted quotation, the invoice with its terms, and the dated chase messages.

Reducing the odds next time

Late payment is partly a systems problem, and the fixes are unglamorous but effective.

• Invoice the day the work is finished, not at the end of the month
• Ask at the start who processes invoices, and send it to them directly
• Ask whether a purchase order number is required before you invoice
• Take a deposit on anything substantial
• Put payment terms and any late interest in the quotation, before work begins
• Shorten your terms — Net 14 rather than Net 30
• Make paying easy: full bank details, a clear reference, and a payment link if you have one