Most late payments are administrative, not adversarial. The invoice went to the wrong inbox, missed an approval cycle, lacked a PO reference, or is simply behind forty others in a queue.
Treating a late invoice as a betrayal on day two costs you the relationship and does not speed up the payment. Treating it as an unpaid invoice on day ninety costs you the money. A schedule solves both.
#The principle: escalate on a timetable, not on emotion
Decide the schedule before anything is late, and follow it regardless of how you feel that week. Consistency is what makes it work — clients learn quickly whose invoices are chased and whose are not.
#Stage 1 — Day 1 past due: the friendly check
Assume administrative failure, because it usually is.
Subject: Invoice 2026-014 — quick check
Hi Sarah, hope the launch went well. Invoice 2026-014 for $6,400 was due yesterday and I have not seen it come through. Could you confirm it reached accounts payable? Happy to resend if it is easier. Thanks!
Short, no accusation, offers to solve the problem. This alone resolves a substantial share of late invoices.
#Stage 2 — Day 7: the phone call
Email is easy to defer. A phone call is not.
Call your contact, not accounts payable. Ask directly: "Has invoice 2026-014 been approved, and do you know when it is scheduled for payment?" That question is specific enough to require a real answer.
Follow up the same day with a written summary of what was agreed. Verbal commitments dissolve; written ones persist.
#Stage 3 — Day 14: the formal notice
Now the tone shifts from collegial to businesslike, still without hostility.
Subject: Overdue: Invoice 2026-014 — $6,400
Hi Sarah, invoice 2026-014 for $6,400 is now 14 days overdue. Per the terms on the invoice, a late fee of 1.5% per month applies to overdue balances from today.
Could you confirm a payment date by Friday? If there is an issue with the invoice I would rather resolve it than have it sit.
Bank details are on the attached copy.
Attach the invoice again. Copy accounts payable. State the consequence factually rather than as a threat.
#Stage 4 — Day 30: stop work and escalate
Two actions, together:
Pause current work. Notify them in writing, without drama: "I am pausing work on the March deliverables until invoice 2026-014 is settled." This is the single most effective lever available, and it is entirely reasonable.
Escalate above your contact. Copy their manager or the finance director. Frame it as a process problem rather than a personal failure — your contact may genuinely have been blocked internally, and giving them cover keeps the relationship usable.
#Beyond day 45
At this point you are dealing with either a company in genuine difficulty or one that pays only when forced.
Options in ascending order:
A formal letter before action, stating the amount, the history and your intention to pursue recovery. In many jurisdictions this is a required step before court action and it frequently produces payment on its own.
Statutory interest and recovery costs. In the UK and EU, commercial debts attract statutory late payment interest plus a fixed recovery sum automatically, whether or not your contract says so. Citing the specific legislation carries more weight than a self-imposed fee.
Small claims court. Designed for exactly this. Fees are modest, you do not need a lawyer, and the process is straightforward for a documented debt with a clear paper trail.
A collection agency, which typically takes 20% to 40%. Worth it only for larger sums and only when the relationship is already over.
#The prevention that matters more than any of this
Take a deposit. Thirty to fifty percent upfront on any new client or substantial project. It filters out clients who were never going to pay and caps your exposure.
Run a credit check on larger corporate clients. Company filings are public in most jurisdictions and take five minutes to check.
Invoice immediately and correctly. Half of all late payments trace back to an invoice that arrived late, went to the wrong place, or was missing a PO reference. The invoice generator handles sequential numbering, explicit due dates and payment instructions so those failure modes do not arise.
Stage payments on longer projects. Never let unbilled work exceed what you can afford to lose.
#The client you should let go
If a client is habitually late, disputes invoices only after the work is delivered, or requires escalation every single time, they are costing you more than the revenue is worth. The time spent chasing is time not spent on work that pays on schedule.
Raise your rates for that client at the next renewal. Either they become worth the friction, or they leave — and both outcomes are improvements.
Frequently asked questions
When should I stop working for a client who has not paid?
A reasonable default is 30 days past due, notified in writing in advance. Continuing to deliver while unpaid increases your exposure and signals that the terms are optional.
Can I charge interest on a late invoice if it was not in the contract?
In the UK and EU, statutory late payment interest and fixed recovery costs apply to commercial transactions automatically, regardless of contract terms. Elsewhere it depends on local law and is far stronger when the term appears in your contract as well as the invoice.
Is it worth taking a client to small claims court?
For a clearly documented debt with a signed contract or accepted proposal, often yes. Fees are modest, no lawyer is needed, and many defendants settle once proceedings are issued. Recovery still depends on the client having assets.