What to Do When a Customer Won't Pay an Invoice

Why is this invoice unpaid?

Before you escalate, find out what you are escalating against, because the right response to each cause is different. An invoice sent to a person who left the company six weeks ago needs an email, not a demand letter. An invoice short by a disputed freight charge needs a credit memo and a conversation. An invoice from a customer who has quietly stopped paying all their suppliers needs the fastest, most formal route available. Treating all three identically either damages a good relationship or wastes weeks on a customer who will never pay.

Spend one phone call establishing which situation you are in. Ask your contact to pull the invoice up in their system and tell you its status — not received, received and unapproved, approved and scheduled, or in dispute. That single question often resolves the matter in one conversation, and when it does not, the answer tells you exactly which step to take next.

• Administrative: wrong billing address, missing purchase order number, invoice never entered, approver on leave
• Process: the customer pays on a check run cycle that your terms did not account for
• Documentation: proof of delivery, signed timesheet, acceptance certificate or rate confirmation missing from their file
• Dispute: a quantity, price, quality or scope disagreement that nobody escalated to you
• Contingent terms: a pay-when-paid or pay-if-paid clause in a subcontract that nobody flagged at the outset
• Cash flow: the customer is solvent but stretching payables, and the squeaky suppliers are getting paid first
• Distress: the customer is genuinely in trouble, in which case speed and position matter more than politeness

What should I do in the first week past due?

The first week is cheap and high-yield. Act promptly and professionally, document everything, and keep the tone transactional. Nothing you do in week one should be adversarial, because at this stage you are most likely dealing with an administrative problem rather than a refusal — and a hard letter sent against a filing error is remembered for years.

• Confirm the invoice was actually received, by the right person, at the right address, with the right purchase order reference
• Re-send it with the supporting documents attached — proof of delivery, signed acceptance, timesheets, rate confirmation
• Call rather than email; a two-minute conversation with accounts payable extracts information a reminder email will not
• Ask directly for a payment date and write it down, with the name of the person who gave it to you
• Note the customer's check run schedule and approval chain so your next invoice lands before the cutoff rather than after
• Log every contact — date, person, substance — because this record becomes the backbone of any later formal step

What is the escalation sequence?

Escalate in order, let each step do its work before moving to the next, and keep every communication in writing even when it starts on the phone. The sequence matters because each stage builds the record the next stage relies on, and because a customer who sees a measured, documented progression understands that you will see it through.

1. 1Courtesy reminder. A short, friendly email a few days past due with the invoice attached, the amount, the due date and a direct request for a payment date. Assume an oversight and make it easy to fix. Send it to both your commercial contact and accounts payable.
2. 2Statement of account and a phone call. Send a statement listing every open item, then call to confirm it was received and ask which invoices are approved for payment. The goal is to convert a vague promise into a named date and a named person.
3. 3Formal written demand. A letter on company letterhead stating the amount, the contractual basis, the documents evidencing performance, a clear payment deadline and what you will do if it passes. Reference any late payment or interest provision in your contract. Send it so that delivery is provable, and send a copy to a senior contact rather than only to accounts payable.
4. 4Stop work or hold shipments, if your contract allows it. Continuing to deliver into a growing unpaid balance converts a collection problem into a bigger one. Check your contract for a suspension right and the notice it requires, then pause further work in writing. This is often the step that produces payment.
5. 5Preserve project-specific remedies where they apply. On private construction work, mechanic's lien rights may attach to the improved property. On public projects, payment bond claims under federal or state public works statutes may be available instead, since public property generally cannot be liened. Both routes depend on notices and filings with strict, state-specific timing, so involve a construction attorney as soon as a project receivable goes seriously late.
6. 6Place the account with a collections agency. A commercial collections firm works on a contingency agreed in advance and brings pressure you cannot apply yourself. Realistically it ends the commercial relationship, so place accounts you have written off relationally, and read the engagement terms on what happens if the customer later pays you directly.
7. 7Small claims or civil action. Small claims courts handle lower-value commercial disputes relatively quickly and often without counsel; larger amounts go to a general civil court and bring real cost and time. Before filing, ask the question that decides it: if you win, can this customer actually pay? A judgment against an empty company is an expensive piece of paper.
8. 8Write it off and close the loop. At some point the recovery is worth less than the attention it consumes. Write the balance off for tax purposes with your accountant, record the customer in your credit notes, and tighten the terms that let the exposure build.

What leverage do I actually have?

Leverage in a payment dispute comes from three places: what your contract says, what the customer still needs from you, and what a formal process would cost them. Most businesses underuse the first and overestimate the third. Read your own terms before you escalate — a clearly drafted late payment provision, a suspension right, a retention of title clause on goods, or an attorney fee recovery clause changes the conversation immediately, and many businesses discover they have one only after the invoice has been late for two months.

Ongoing need is the strongest everyday lever. A customer who requires next month's deliveries, next week's staffing cover or continued access to your parts has a practical reason to clear the balance that no letter can replicate. Use it early and plainly rather than as a threat at the end: a simple written note that further work is on hold pending payment of approved invoices is more effective, and more professional, than three further reminders. Reserve formal process for customers who no longer need you, because against those the only remaining leverage is cost and time.

What is different about construction and public projects?

Construction receivables sit in their own world. Payment frequently flows through a chain — owner to general contractor to subcontractor to supplier — and the terms in between often include pay-when-paid or pay-if-paid provisions whose enforceability varies by state. Retainage may hold back part of every invoice until a project completes. The practical consequence is that a late invoice is often not a dispute with your direct customer at all, but a blockage further up the chain, and the diagnosis in week one should establish where the money actually is.

Against that, construction gives you remedies other industries do not have. On private work, a mechanic's lien attaches a claim to the improved property itself, which gets the owner's attention because it clouds title. On public projects, the property generally cannot be liened, and the substitute is a claim against a payment bond posted by the prime contractor — the mechanism created federally under the Miller Act for federal work and mirrored by Little Miller Act statutes for state and local projects. Both routes run on preliminary notices and filing windows that are strict, unforgiving and different in every state.

Should I use a collection agency, go to court, or write it off?

All three are real options and each has a cost that should be modeled before you commit. A commercial collections firm charges a contingency negotiated up front, requires no filing, and is usually faster to start, but it effectively ends the relationship and its leverage is persistence rather than legal force. Agencies work best where a solvent customer is simply deprioritizing you, and barely at all where the customer genuinely has no money.

Litigation converts a debt into a judgment, which is a stronger instrument, but a judgment is not cash. Small claims is proportionate for smaller balances and often proceeds without counsel, though limits, procedures and whether a company may appear without a lawyer differ by state. Larger claims need counsel and realistic estimates of cost and timeline. Run the same test before either route: estimate the likely recovery, subtract the contingency or legal cost, subtract your own management time, and compare the result against closing the file.

Write-off is the third answer and often the right one. The signals are clear enough once you look for them — the customer has stopped responding, other suppliers report the same, the entity appears to have ceased trading, or the recoverable amount no longer justifies the next step. Treat it as an accounting action rather than a defeat: work it through with your accountant so the deduction is taken correctly, flag the customer in your internal credit records, and run a short post-mortem on how the exposure grew. Usually the answer is that nobody checked their credit at the outset and nobody stopped shipping when the first invoice aged.

How do I stop this happening again?

The cheapest collection is the one you never have to make. Most chronic late payment is designed into the sales process rather than inflicted at the end of it, and tightening a handful of habits removes a surprising proportion of the problem within a quarter.

• Run a commercial credit check before extending terms to a new customer, and set a credit limit in writing
• Get the terms agreed in a signed contract or accepted purchase order, including late payment provisions and a suspension right
• Invoice the day work is accepted, not at month end, and send it to the person who actually approves payment
• Attach the proof of delivery, signed timesheet or acceptance certificate to every invoice so there is nothing to ask you for
• Learn each customer's approval chain and check run cycle, and bill to land ahead of their cutoff
• Review your aging report weekly and act at day one past due, not day thirty
• Watch concentration: one customer at a large share of your ledger is a business risk, not just a collections risk
• Consider non-recourse factoring or credit insurance where you need protection against a customer's insolvency, remembering that neither responds to a commercial dispute

Can financing help while I chase?

Financing is a cash flow tool, not a collections remedy, and it is worth being clear about which problem it solves. Receivables financing advances 80% to 95% of invoice value against invoices your customers are not disputing, which keeps payroll and suppliers covered while a slow payer works through its cycle. Full-service invoice factoring adds commercial credit checks on your customers and professional collections handling, which for a small business is often worth as much as the cash — it replaces a job nobody in the company wants to do with one somebody does full time.

What financing does not do is fund an invoice that is already deeply delinquent or in dispute. Funders advance against performing receivables, not distressed ones, and under a recourse facility an invoice that goes unpaid past the agreed period is charged back to you. The useful time to put a facility in place is before you need it, when your ledger is clean and your customers are current — not in the week you discover your largest account has stopped paying.