The ladder below runs from cheapest to most expensive. That order is not politeness. The top rungs cost minutes and close most accounts, so any rung you skip past is one you paid for without needing to.
First, rule out friction: the pause-and-call
Most unpaid invoices are not refusals. They are friction. The invoice went to an address that forwards to nobody. The office manager who approved the work left. The customer thinks a change you made was included and is waiting for you to bring it up. Or something small went wrong at the end of the job and they are avoiding the conversation rather than the bill.
None of that is visible from the outside, and none of it is fixed by a fourth reminder email. Automated reminders are the right tool for the first two weeks, and after that they stop carrying information. The reminder cadence runs before things go wrong. This is where it stops working.
So call. The call has one job, which is to sort the account: they did not know, they cannot pay, or they will not pay. Confirm they received the invoice, then ask one open question, something close to "is there anything on this invoice that doesn't match what we agreed?" Then stop talking.
Did not know ends on the phone. Cannot pay is worth a written payment plan with dates on it, because a judgment against someone with no money returns nothing and costs you the filing fee to obtain. Will not pay is the only category the rest of this guide is about, and it is the smallest of the three.
Write down the date of the call and what was said. Everything below gets stronger with a contact history and weaker without one.
The final notice: a date and a consequence
A final notice is not another reminder with firmer wording. It has two elements a reminder does not: a specific date, and a specific next step you are willing to take on that date.
The consequence has to be real. A threat you do not carry out teaches this customer that your notices are noise, and it can create a problem of its own. Even where the Fair Debt Collection Practices Act does not reach a business collecting its own invoices, the Federal Trade Commission treats false threats of legal action as deceptive under Section 5 of the FTC Act.3 If the notice says you will file, be ready to file.
Two related mistakes come from the same impulse, which is trying to sound more serious than you are. The first is inventing a collections department. The FDCPA's definition of a debt collector expressly includes a creditor who, while collecting its own debts, "uses any name other than his own which would indicate that a third person is collecting."3 The letterhead meant to add weight is what converts you into a regulated debt collector, with validation notices and required disclosures attached. The second is telling other people about the debt. The FTC has taken action under Section 5 against first-party creditors who revealed a debt to someone other than the debtor.3 The general contractor, the tenant, and a review page are all the wrong audience.
A workable final notice states the amount, the invoice number and date, the work it covers, the dates of prior contacts, the date payment is due, and the step that follows. Send it so delivery leaves a record. Certified mail with a copy by email does that for a few dollars.
If your contract provides for a late fee, this is the notice where the accrued fee appears. If it does not, adding one now is not enforceable and it hands the customer a reason to dispute the whole balance. That distinction is the subject of when to charge a late fee on an unpaid invoice.
The demand letter that gets taken seriously
A demand letter differs from a final notice in what it points at. It references the contract by date, states the amount owed under it, and names the legal step and its deadline.
What makes a demand letter credible is not the tone. It is the file behind it: the signed quote, the written approvals for anything added mid-job, the dated completion record, the invoice, and the notice history, all attached. A customer deciding whether to test you is weighing whether you can prove the scope, and an attached approval trail answers that before a lawyer has to.
An attorney-drafted letter carries more weight and costs money. Get a flat fee quoted first and compare it against the invoice, not against the principle. Whether you can recover that cost depends on your contract and your state, and many small service contracts carry no attorney-fee clause at all, so the letter is usually a cost you absorb whether or not it works.
Small claims: when the math works
Small claims is the rung most articles stop at, usually with the filing fee quoted and nothing else. The filing fee is the cheapest part.
In California, small claims covers up to $12,500 for an individual and up to $6,250 if you are a business.4 That distinction is worth reading twice, because it is set by how you organized, not by what you are owed. Two operators who did the same $9,000 job have different ceilings on the same unpaid invoice depending on whether the contract was signed by a sole proprietor or by an LLC. Filing fees run $30 for claims of $1,500 or less, $50 up to $5,000, and $75 above that, with $15 per defendant if the clerk serves the claim for you.5 A hearing usually lands one to two months out, and you cannot bring a lawyer.4
Now the part that decides whether this rung is worth climbing. Winning is not collecting. The California courts say it plainly: if you win, you have to collect the money yourself, and the court does not do it for you.4 Post-judgment steps carry their own fees, currently $40 to issue a writ of execution, $40 for an abstract of judgment, and $60 for an order examining the judgment debtor about what they own.5 Each of those is another form and, in the case of the debtor examination, another appearance.
Which reframes the question. Not whether you can win, since a documented invoice against a customer who stopped paying is a strong case, but whether this defendant is collectible. A homeowner with a mortgage and a paycheck usually is. A dissolved LLC is not, and a judgment against one is a piece of paper you paid $50 for.
A pair of mechanics decides cases before they are heard. Sue the entity named on the contract, exactly as it is named, because a judgment against a business name that does not legally exist is not enforceable against the people behind it. And if you filed the case and lose, you cannot appeal.4 Limits and procedure vary by state, so confirm your own before counting on any of these numbers.
The lien deadline does not wait for your patience
This section sits fifth on the page and first on the calendar. Every other rung can be climbed late. This one cannot.
In California, a direct contractor has to record a claim of lien after completing the contract and before the earlier of two dates: ninety days after completion of the work of improvement, or sixty days after the owner records a notice of completion.2 Read the second half of that again. The owner controls a filing that shortens your window by a month, and you may not be told it happened. The clock runs from the work, not from the dispute, so a customer who is polite and slow for two months has already spent most of your lien rights for you.
If you are a subcontractor or a supplier rather than the direct contractor, an earlier deadline applies. A preliminary notice has to go out before work begins or within twenty days after, and without it the lien right is lost.6 That notice comes due before any dispute exists, which makes it a paperwork habit rather than a collection step. The direct contractor and laborers do not have to send it.6
Recording the lien is also not the end of it. The claim has to be enforced by a foreclosure action within ninety days of recording or it expires on its own.6
A lien is the wrong instrument for a $600 service call. It is a cloud on title, so it bites when the owner goes to sell or refinance, which can be years out. On a jobsite with a lender behind it, the same filing gets attention in days. Recording one improperly carries its own exposure, and every deadline above is state law with real variation, so this is the rung where a licensed attorney in your state earns the fee. The part that transfers everywhere: the lien window closes from the completion date, whatever rung you happen to be standing on.
Collections, and the number where you write it off
A collection agency is a price rather than a rescue. You hand over the file and a percentage of anything recovered, and you spend none of your own hours. That percentage is set by the agreement you sign, so get it in writing before you place the account.
Know two things before placing. A third-party agency collecting your invoice is a debt collector under the FDCPA, and its conduct is regulated in ways your own collection efforts may not be.3 That behavior attaches to your name in the customer's memory regardless. And placement generally ends the relationship, so decide first whether this customer is worth more to you than this invoice.
Then there is the write-off. The test is not the size of the debt. It is whether the amount you still expect to recover, discounted by the odds of collecting it, beats the value of the hours it will take, priced at your loaded cost per working hour. The alternative use of those hours is billable work.
Writing off is a business decision, not a legal deadline. In California an action on a written contract can be brought within four years.1 You can stop spending hours on an account without surrendering the claim, so if the customer resurfaces the claim is generally still there. Handle the accounting side with your tax preparer.
Worked example: the ladder priced on an $1,850 invoice
Assume an $1,850 invoice, 45 days past due, a customer who has gone quiet, and a documented file. California fees are used because they are published; substitute your own state. The hour counts and the loaded cost of $65 per working hour are illustrative.
| Rung | Out of pocket | Your hours |
|---|---|---|
| Pause-and-call | $0 | 0.25 |
| Final notice, certified | Postage | 0.5 |
| Demand letter, self-drafted | Postage | 1.0 |
| Small claims filing and clerk service | $65 | 2.0 |
| Preparing and attending the hearing | $0 | 4.0 |
| Writ of execution and abstract of judgment | $80 | 1.0 |
| Judgment debtor examination, if needed | $60 | 3.0 |
That is roughly $205 of court and service fees plus 11.75 hours. At $65 an hour of loaded cost, the hours are worth about $764, so the full climb runs near $969 against an $1,850 invoice. Recovering the invoice still nets you money, but only if the defendant is collectible, and only if you stop at the rung where they pay.
Compare a placement with a collection agency at an illustrative one-third contingency: about $1,233 net if they recover in full, and zero hours from you. Neither route is certain. What separates them is that one costs days and the other costs margin.
Now run the same ladder on a $340 invoice. The court and service fees drop to about $185, but the hours do not move, because filing and appearing take the same time regardless of the amount. The effort alone exceeds the invoice several times over before anyone has been paid. On that number, the correct answer is the first two rungs and then a write-off.
Which is the real finding in the table. The rungs are cheap at the top and expensive at the bottom, and the call that costs fifteen minutes closes most accounts. Working the ladder in order is not patience. It is the only version of this that is cheaper than the debt.
The paperwork that decides all of it, before it starts
Every rung above runs on documents that had to exist before anyone disagreed. The signed quote that fixes the scope. The written approval for anything added mid-job. The dated invoice carrying the terms. The completion record, which is what both the lien deadline and the limitations period run from. The contact history behind the notices.
A customer refusing to pay a fully documented invoice is a collection problem, and collection problems have a ladder. A customer disputing an invoice you cannot substantiate is a different situation entirely, and no rung fixes it, because each one asks you to prove what was agreed.
Most of the work happens upstream, in two habits. Put the terms on the invoice itself instead of leaving them to be inferred, covered in what payment terms to put on an invoice. And take a deposit, which is the single strongest lever available, because it caps your exposure at the unearned portion of the job before you have bought a dollar of materials. That structure is worked through in how to ask a customer for a deposit.
The invoices that end up on this page are almost never the ones where the file was complete.
The rung before all of them is the quote
We built EosLog's quote generator so the scope and the price live on one dated document the customer approves before the work starts. That document is what every step above asks you to produce.
No account required. You can also create a free EosLog account to keep the approved quote and the invoice on one job record, or see the plans first.
Sources and further reading
- California Legislative Information, Code of Civil Procedure section 337 (four years to bring an action on a contract founded upon an instrument in writing).
- California Legislative Information, Civil Code section 8412 (a direct contractor must record a claim of lien after completing the direct contract and before the earlier of 90 days after completion of the work of improvement or 60 days after the owner records a notice of completion).
- Federal Trade Commission, Think your company's not covered by the FDCPA? You may want to think again. (FDCPA section 803(6) covers a creditor collecting its own debts under a name indicating a third party; FTC Act Section 5 reaches deceptive collection practices including false threats of legal action and revealing a debt to someone other than the debtor).
- California Courts Self Help Guide, Small claims in California (limit of $12,500, or $6,250 for a business; filing fee $30 to $100; hearing typically 1 to 2 months out; no attorney; the winner collects the judgment, not the court; a plaintiff cannot appeal).
- Judicial Council of California, Statewide Civil Fee Schedule, effective January 1, 2026 (small claims filing $30 / $50 / $75 by claim size, $100 for more than 12 claims in 12 months, $15 per defendant for clerk service, $40 writ of execution, $40 abstract of judgment, $60 application for order of examination of judgment debtor).
- California Contractors State License Board, How to Prevent a Mechanics Lien and What if a Mechanics Lien is Filed on Your Property? (preliminary notice within 20 days, not required from the direct contractor or laborers; a recorded notice of completion shortens the lien window; a foreclosure action must be filed within 90 days of recording the lien).
This guide reflects general US service-business collection practice as of 2026 and is not legal advice. Small claims limits, filing fees, mechanics lien deadlines, and limitations periods are set by state law and vary widely; the California figures above are used because they are published and current, not because they apply to you. Every hour count and hourly cost in the worked example is illustrative. Confirm your own state's deadlines with a licensed attorney before relying on any of them, and speak with your tax preparer about writing off a bad debt.