Idaho prejudgment interest rate
United States Idaho’s prejudgment interest rate — when a court awards it.
→ All Idaho judgment & prejudgment interest rates
Fixed by statute Fixed by statute
2026 Idaho prejudgment interest at a glance
- Current rate
- 12% per year
- Effective date
- July 9, 2026
- Controlling authority
- Idaho Code §28-22-104(1) (12% general); §12-301 / §28-22-104(2) (tort)
- Rate basis
- Fixed by statute
- Source checked
- July 9, 2026
- Recorded history
- 1 data point
Idaho prejudgment interest is 12% per year, as simple interest under Idaho Code 28-22-104(1). Prejudgment interest is available ONLY where the claim is liquidated OR the amount is ascertainable by a mere mathematical process.
When Idaho prejudgment interest applies
Prejudgment interest is available ONLY where the claim is liquidated OR the amount is ascertainable by a mere mathematical process. It is BARRED on unliquidated damages. Generally NOT available in tort cases unless the damages are reasonably ascertainable/liquidated (Davis v. Prof'l Bus. Servs.; Bouten Constr. v. H.F. Magnuson). Contract claims qualify when the sum due is fixed or mathematically determinable. If an express written contract sets a different interest rate, that rate applies instead of 12%.
When it starts accruing
Interest accrues from the date the money became "due" (for contract, the date of breach), provided that at that point the amount was liquidated or ascertainable by mathematical computation.
Simple or compound
Simple.
→ Compare with the Idaho post-judgment interest rate (interest after judgment)
Idaho general/contract prejudgment interest is 12% simple (Idaho Code §28-22-104(1)). SEPARATELY, in tort actions for personal injury, property damage, or wrongful death where the claimant serves an offer of settlement, prejudgment interest accrues at the §28-22-104(2) variable rate (currently 8.875%) under §12-301 — not the 12% general rate. Verified 2026-07-11. Not legal advice.
Current recorded observation
| Effective date | Rate | Basis |
|---|---|---|
| July 9, 2026 | 12% | Statute |
Source & provenance
Observation recorded July 9, 2026 (00:00 UTC) from the cited source (Idaho — legislature.idaho.gov):
https://legislature.idaho.gov/statutesrules/idstat/title28/t28ch22/sect28-22-104/
Cite this page
StatuteRates. “Idaho Prejudgment Interest Rate.” StatuteRates.com. Accessed today. https://statuterates.com/rates/idaho-prejudgment-rate/ Rate recorded under Idaho Code §28-22-104(1) (12% general); §12-301 / §28-22-104(2) (tort), effective July 9, 2026.