What to do when a client will not pay

There is a difference between an invoice that is late and a client who will not pay. The first is normal and resolves with reminders. The second requires a different set of decisions, and making them early costs less than making them at month four.

Establish which one you are dealing with

Ask three questions:

• Are they replying at all? Silence is a much worse signal than a difficult reply.
• Is there a dispute, and did they raise it before or after the invoice went late? Complaints that appear only after a payment chase are usually a delay tactic.
• Are they still paying other suppliers? Trouble paying everyone is a solvency issue that changes your strategy entirely, because in an insolvency you want to be early and documented.

Step one, exhaust the polite route properly

Before escalating, make sure you have covered the boring failure modes: wrong billing address, missing purchase order number, supplier registration incomplete, invoice never reaching accounts payable, or your contact having left the company. A surprising share of hopeless cases are one of these.

Send the invoice again, to a second recipient, with a direct question about their process.

Step two, stop work and say so

If the project is ongoing, pausing is your strongest lever and it works best while you still hold something they need. Say it plainly and without drama:

"I have paused work on the project as of today while invoice 2026-041 is outstanding. Happy to pick straight back up once it clears."

Do not delete anything, do not disable anything you have already handed over, and do not threaten. Simply stop producing new value.

Step three, the formal demand

A final notice, sent by email and post if the amount justifies it. It should be short and factual: the invoice number and date, the work delivered, the amount outstanding, the terms agreed, the reminders already sent with dates, a payment deadline usually 7 to 14 days, and a statement of what happens next.

The change in register matters. Everything before this was correspondence. This is a document, and it is the one you will attach to any subsequent process.

Step four, choose a route

• Collections agency. They take a percentage, typically substantial, and you get no relationship afterwards. Reasonable for mid size amounts you have written off emotionally.
• Small claims. Cheap, designed to be used without a lawyer, and effective against a solvent client who is simply ignoring you. Limits and process vary by jurisdiction. Judgment is not payment, but many clients settle the moment a filing appears.
• Lawyer's letter. Often the highest return per dollar. A single letter on a firm's letterhead resolves a meaningful share of cases for a modest fixed fee.
• Write it off. Sometimes correct. Calculate the hours you would spend recovering, price them at your rate, and compare honestly.

Do the arithmetic before escalating

Recovering 800 through a process that consumes ten hours of your attention is a loss even if you win. Recovering 12,000 is worth real effort. Set the threshold in advance, while you are calm, so the decision is not made in the middle of an emotional week.

Prevent the repeat

Every unpaid invoice contains a lesson about your own process. Usually one of these:

• No deposit, so you carried the entire risk.
• Milestones too large, so a single failure was expensive.
• Terms and late fees never stated in writing.
• No billing contact collected, so the invoice went to one person who left.
• Warning signs at the proposal stage that were ignored because the pipeline was thin.

Fix the one that applies and the category of problem shrinks permanently.

TL;DR

• Rule out process failures first: wrong recipient, missing PO, incomplete supplier setup.
• Pause work early, while you still hold leverage, and say so without drama.
• Send a factual formal demand, then choose between collections, small claims, a lawyer's letter, or a write off.
• Do the recovery arithmetic in advance, and fix the process gap that let it happen.