Sue for Unpaid Invoice in Arizona Small Claims Court

Does Your Invoice Qualify?

Arizona's Small Claims Division handles monetary disputes up to $5,000. If a client owes you $3,800 on a net-30 invoice that's 90 days overdue, small claims is built for exactly this.

Your statute of limitations depends on whether the contract was written or oral. Written contracts (including signed agreements, purchase orders, and emailed scope-of-work confirmations) get six years under A.R.S. § 12-548. Oral agreements and open accounts get three years under A.R.S. § 12-543. The clock starts on the date the payment was due, not the date you did the work.

Send a Formal Demand First

Before filing, send a written demand via certified mail with return receipt requested. State the invoice number, amount, original due date, and that you expect payment within 10–14 days. Close with a clear statement that you'll file in Arizona Justice Court if they don't pay.

The demand letter serves double duty: it gives the debtor a last chance to pay without court costs, and it becomes evidence of your good-faith attempt to resolve the dispute. Keep the signed return receipt — you'll include it in your evidence at the hearing.

Choosing the Right Precinct

File in the Justice Court precinct where the debtor resides or operates a business. For written contracts, you can also file where the contract was to be performed. If the client is a business entity, verify their legal name and statutory agent on the Arizona Corporation Commission eCorp portal before filing.

If you're an individual freelancer, you represent yourself. A corporation must appear through a full-time officer or authorized full-time employee and provide an authorization letter on corporate letterhead. An LLC must appear through a member, manager, or authorized full-time employee.

Calculating Your Claim

Add up everything you're owed:

• The unpaid invoice amount — your principal claim
• Pre-judgment interest — a court may award interest on a liquidated debt (an amount calculable with mathematical certainty) under A.R.S. § 44-1201. The rate is 10% per annum unless your written agreement specifies a different rate. Interest accrues from the date the payment was due.
• Filing and service costs — request eligible expenses, such as the filing fee, certified mail costs, and process server fees. The court decides what costs to award.

Make sure your total doesn't exceed $5,000 (excluding court costs and post-judgment interest, which sit outside the cap).

At the Hearing

Unpaid invoice cases are evidence-driven. Bring originals of:

• The signed contract, proposal, or email agreement
• The invoice itself, with terms and due date visible
• Proof of delivery — emails confirming the work was completed, delivery receipts, or client sign-off
• Payment history — if they paid part of it, show what's still outstanding
• The demand letter and return receipt
• Your interest calculation, showing the rate and period

Present it chronologically: agreement, work performed, invoice sent, payment not received, demand sent, still unpaid. The hearing officer will ask whether the debtor disputes that the work was done or that the money is owed.

After Judgment

If the court rules in your favor and the debtor still won't pay voluntarily, Arizona provides enforcement tools: writs of garnishment (bank accounts and wages), writs of execution (seizure of personal property), and debtor examinations (court-ordered disclosure of assets). The court doesn't collect for you — you'll need to pursue these steps yourself.

The Arizona Small Claims Filing Guide covers the full process from demand letter through post-judgment enforcement options, with an expense tracker to ensure every recoverable cost makes it onto your complaint.

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