Direct answer

A client never paid your invoice. Yes, you can usually take them to small claims court. Here is the evidence you need.

In most US states, small claims court is built for exactly this: one person did the work, the other person did not pay, and the amount is a typical freelance invoice, not a corporate lawsuit. You do not need a lawyer to file in most places. What you need is a clean evidence packet, in the order a judge reads it, so the story is obvious in five minutes: you agreed on the work, you delivered it, the client accepted or used it, you billed it, and they did not pay.

Before you file, make your delivery exhibit checkable: check any Zambo receipt free at zambo.dev/verify, with no signup. If your work ran through Zambo, its handover is the link you print for the delivery and acceptance exhibit below.

Updated October 24, 2026. This page is practical guidance, not legal advice.

First, check that small claims fits your case

Small claims limits vary by state, and that variation is the first honest limit on this page. Some states cap claims at a few thousand dollars, others allow ten thousand dollars or more, and the cap can differ if you file as an individual or as a business. Filing fees vary too, and so do the filing window, the forms, and how the client must be served with notice.

So do this check before anything else, on your state or county court website or self help center:

Is your invoice amount under the small claims cap in that state? If it is over, you may have to reduce the claim to the cap or use a different court.
What is the filing fee, and can it be added to what you are claiming where your state allows that?
What is the deadline to file for this kind of claim, and are you inside it?
Where should the case be filed: where you are, where the client is, or where the work was done?

If the amount fits and you are inside the window, the next job is not writing a speech. It is assembling the packet.

The evidence packet, in the order a judge reads it

Bring three copies of everything: one for the judge, one for the client, one for you. Put the pages in this order, with a one page cover sheet that lists what is inside.

1. The agreement. The contract, statement of work, or signed proposal if you have one. If you do not, print the email or message thread where scope, price or rate, and deadline were discussed and the client said yes in writing. Add any earlier paid invoices on the same terms if they help show this was the standing arrangement. The judge is looking for one thing here: was there a real agreement, and what were its terms?

2. Proof of delivery, with a timestamp the client cannot rewrite. A file sent is not the same as a file proved. Bring the delivery email with its full date, the shared folder history if you have it, and, strongest of all, a delivery record saved at the time the work was handed over. A screenshot you made later is easy to argue with. A record saved at delivery, with the date and the result attached, is not. More on the Zambo version of this exhibit is in the next section, and the general method is covered in prove I delivered the work.

3. Proof of acceptance or use. The client reply that says the work looks good, the sign-off note, a screenshot of the work live on their site or in their product, or the acceptance record from the handover itself. If the client used the work in public, print that page with its date. Acceptance answers the most common defense, which is that the work never arrived or was never approved. For the next job, the habit that creates this exhibit on purpose is in get written sign-off from a client.

4. The invoice and the chase trail. The invoice itself, with its number, date, due date, and line items. Then every reminder you sent, in date order, with the client replies if any. Keep the tone of your own reminders factual in print, even if you were frustrated at the time. The trail shows you billed clearly, gave a fair chance to pay, and were ignored or stalled. If the dispute is still at this stage and has not reached court yet, start with client disputing my invoice.

5. The amount math, on one page. One page, no spreadsheet printout with tiny cells. Show the agreed price or the hours and rate, what was already paid if anything, any late fee only if your agreement actually provides for one, and the balance you are claiming. The total on this page must match the total on your filing form exactly. If a judge has to hunt for how you got the number, you have already made the case harder than it needs to be.

Where a Zambo handover fits in the packet

Zambo is the verifiable work layer for AI, and HANDOVER is its flagship product. If the work you delivered was done with AI help and ran through Zambo, the handover is exhibits 2 and 3 in one place.

Here is how that works in practice. When you finish the job, you close it with a handover: the goal, the steps that ran, the outputs, and the receipts saved when each call ran. The client opens that handover and accepts it, and that acceptance is recorded too. The handover has a public proof link. Anyone with the link can open the record and check it at zambo.dev/verify: the check recomputes the saved record and confirms the saved result was not changed after it was saved.

For court, you do a simple thing with that link. Print the handover page and the verification result, write the link itself on your cover sheet, and bring all of it. That printout is your delivery and acceptance exhibit. It does not argue for you, and it does not need to. It shows what was delivered, when the record was saved, and that the client accepted that handover, in a form the other side cannot quietly edit after the fact. The background on how handovers are structured is in AI agent handover.

The receipt format under the handover is AER-1, an open Internet-Draft (draft-zambo-aer1-26), not a finalized standard. You do not need to explain the format to a judge. You only need the exhibit to check out when anyone opens the link.

What to do on the day, in order

1. File and serve correctly. Follow your court instructions for service exactly. A strong packet filed with bad service can be delayed or dismissed on procedure alone.

2. Rehearse the five minute version. Agreement, delivery, acceptance, invoice, balance. One or two sentences per exhibit, pointing at the page as you say it.

3. Bring the links as well as the paper. Write the handover proof link and the verify page address on the cover sheet, so the record can be checked live if anyone wants to.

4. Answer quality complaints with the record, then stop. If the client says the work was poor, point to what was delivered and to the acceptance. Do not redesign the work from the witness stand. The judge decides the rest.

5. If you win, ask the court how collection works. A judgment and a payment are two different steps in many states, and the court clerk can tell you the local collection options and forms.

Honest limits

Filing fees, caps, forms, service rules, and timelines vary by state and sometimes by county. This page is practical guidance for organizing your evidence, not legal advice, and it is not a substitute for your court self help center or a lawyer for a large or complicated claim.

A verifiable receipt proves a narrow and useful thing: the saved result was not changed after it was saved. It does not prove the work was good, the price was fair, or the advice in the work was right. If the client disputes quality, the record shows what was delivered and what was accepted, with dates. The judge weighs quality, the agreement, and everything else, and decides. The record makes the facts checkable. It does not decide the case.

It also only covers work that actually left a record. Delivery done entirely outside any recorded path has to be proved the older way, with emails, file histories, and the client own replies. Bring those too. A packet with both is stronger than either alone.

Set up the record before the next invoice is due

The cheapest time to build a court ready packet is while the work is running, not after a client goes quiet. Work run through the Zambo MCP endpoint at zambo.dev/mcp (153 tools) saves its result when the call runs and returns a verifiable AER-1 receipt for every call. Close the job with a handover, get the acceptance recorded, and exhibits 2 and 3 already exist if you ever need them. Start free: 20 free calls per day, then they upgrade. The Day Pass is $0.99 for 24 hours. Checking any receipt is always free at zambo.dev/verify.

Questions, answered

How much can I claim in small claims court?

It depends on your state. Caps vary widely, from a few thousand dollars in some states to ten thousand dollars or more in others, and some states set a different cap for individuals and for businesses. A typical freelance invoice fits under the cap in most states. Check the cap, the filing fee, and the filing window on your state or county court website before you file, because claiming more than the cap can mean reducing your claim to the cap or moving the case to a different court.

How long does a small claims case take?

Often a few weeks to a few months from filing to hearing, depending on how busy your local court is and how the client has to be served. The hearing itself is usually short, often under an hour. That is why the packet matters: you may only get a few minutes to walk through it, so it should be in order, printed, and easy to follow without extra explanation.

What if the client is in another state?

You can still have options, but jurisdiction gets more complicated. In general, a case is filed where the client lives or does business, or where the work was agreed or performed, and the exact rule is state law. An out of state client can also make collecting harder even if you win. Check your court self help page or a local legal aid clinic for the rule that applies to your facts before you pay a filing fee.

What if I have no written contract?

You are not automatically out of luck. Courts look at the full record: the email or message thread where scope and price were discussed, a proposal the client approved in writing, earlier paid invoices on the same terms, and proof the client received and used the work. That material can show an agreement even without a formal contract document. Bring the thread in full, not just the one friendly reply, and let the sequence speak for itself.

What evidence matters most for an unpaid invoice?

Delivery plus acceptance, together. The agreement shows what was promised and the invoice shows what was charged, but the pair that answers the usual defense is proof the work was delivered on a date the client cannot rewrite, and proof the client accepted or used it after that. A delivery record with a timestamp and an acceptance record, for example a handover Accept record or a reply confirming receipt, carry more weight than a stack of drafts with no dates attached.

Start where the work starts: run the next job through zambo.dev/mcp, close it with a handover, and check any receipt free at zambo.dev/verify. If you only need a day to rebuild a packet, the Day Pass is at zambo.dev/day-pass.

Proof works best when it travels with the work itself. The AER-1 badge kit turns verifiable receipts into an embeddable badge for project pages, docs, and profiles, so anyone who sees the claim can reach the check in one click.