Reference · Arizona · 2026
Arizona late payment interest rate
When your contract sets no rate, the Arizona figure for interest on an overdue B2B invoice is 10%, under Ariz. Rev. Stat. § 44-1201(A).
Any rate may be agreed in writing. Court-awarded prejudgment interest on liquidated claims uses the lower § 44-1201(B) rate (prime + 1).
- Rate
- 10%
- Statute
- Ariz. Rev. Stat. § 44-1201(A)
- Type
- Fixed by statute.
- Source
- azleg.gov · verified July 9, 2026
What 10% comes to on an unpaid invoice
Simple interest at 10% a year on a 365-day year. Count the days from when interest starts to run in Arizona, which is not always the due date.
| Invoice | 30 days | 60 days | 90 days |
|---|---|---|---|
| $5,000 | $41.10 | $82.19 | $123.29 |
| $10,000 | $82.19 | $164.38 | $246.58 |
| $50,000 | $410.96 | $821.92 | $1,232.88 |
Work out the interest on your invoice
Prefilled with Arizona's legal rate of 10%. If your contract sets a rate, use that instead.
Interest you can claim
$164.38
$10,164.38 with the invoice · $2.74 a day
The ceiling
How high can a late fee go in Arizona?
Your contract decides. The rate above only applies when your terms are silent. Between businesses, an agreed late-interest rate or late fee replaces it, within two limits: the state's ceiling on agreed rates, and the rule that a late fee must compensate you rather than punish the customer.
Arizona's ceiling on an agreed rate wasn't part of our verified research, so check the state's usury law, or ask a lawyer licensed in Arizona, before writing the common 1.5%-a-month (18%) rate into your terms.
Late payment wording for a Arizona invoice
On your invoice
Payment is due by the date shown on this invoice. Late payments are subject to interest at 10% a year, the legal rate under Ariz. Rev. Stat. § 44-1201(A).
This restates what Arizona law applies when your contract is silent. If your contract sets a rate, quote that instead. The wording doesn't say when interest starts, because that differs by state; the note at the top of this page covers it where Arizona law sets it.
How Arizona compares
Of the 46 states with a rate that applies on its own, 7 set a higher one and 33 a lower one. The middle of the range is 8%.
Same 10% figure: California, Hawaii, Kansas, Montana and Utah.
Interest is the fallback. Getting paid on time is the plan.
DueTrail turns overdue invoices into managed cases with reviewable reminders and recorded promises to pay, so invoices get settled before anyone reaches for Ariz. Rev. Stat. § 44-1201(A).