One plan. Everything.
The calculators are free forever. The plan is for tracking every receivable, both clocks, and generating statute-cited demand letters on your own letterhead.
Texas: supported service area
InterestDue supports Texas projects today: TX prompt-pay interest (private and public work) and TX retainage, statute-cited. Georgia and California calculators are available. More states are coming soon. If your projects are outside Texas, hold off on subscribing. Your state is coming.
$79/ month
Texas is the supported service area today (more states coming soon). Every project, every deadline, every letter: unlimited projects, computed statutory interest, demand letters, and both clocks on every receivable.
- Unlimited projects and receivables
- Computed statutory interest with the statute cited on every figure
- Both clocks on every receivable: interest up, lien and notice deadlines down
- Statute-cited demand letters on your own letterhead
- Rules versioned by contract date, with a public rule-change log
14-day free trial. Cancel anytime from the billing portal.
Compare: a per-document service such as Levelset charges $59 per document (verified 2026-07-13). InterestDue is one flat price for unlimited letters and projects.