Methodology & sources

Each series below shows its authority, how the value is obtained, and its confidence.

The rate series

IRS §6621 rates

The IRS sets its interest rates each quarter as the federal short-term rate plus a fixed spread that depends on the category: +3 points for underpayments and non-corporate overpayments, +2 for corporate overpayments, +5 for large corporate underpayments, and +0.5 for the GATT portion of large corporate overpayments. We read the published quarterly figures directly from the IRS and record each with its effective quarter — these are published values.

The federal post-judgment rate (28 U.S.C. §1961)

Federal law defines this rate as the weekly average 1-year Treasury constant maturity yield for the calendar week preceding the date of judgment. The U.S. Courts publish that rule but not the number. We compute it from the Federal Reserve's official H.15 1-year Treasury series (daily), averaged by week, and label it a derived value with medium confidence. Always confirm the exact applicable week against your district court's own published table before relying on it.

UK statutory late-payment interest (Late Payment Act 1998)

UK statutory interest on late commercial (B2B) debts is the Bank of England base rate plus 8 percentage points — but it is fixed for six-month periods using the base rate in force on the reference date: 31 December (for debts falling due Jan–Jun) or 30 June (for Jul–Dec). We track the Bank of England base rate directly (published) and compute the semi-annual statutory rate from it (derived), applying the correct reference date for each period.

EU Late Payment Directive reference rate (2011/7/EU)

The Directive's reference rate is the ECB main refinancing rate in force on the first calendar day of each half-year (1 January / 1 July); a member state's statutory rate is that reference plus at least 8 percentage points (the floor most states use; some add more). We track the ECB main refinancing rate directly (published) and compute the semi-annual reference (derived). Apply your member state's margin to get the statutory rate.

Data sources

• Alaska — public.courts.alaska.gov — Alaska judgment interest (Alaska Stat. 09.30.070(a)). https://public.courts.alaska.gov/web/forms/docs/adm-505.pdf. Government edict — not subject to copyright.
• Alaska — public.courts.alaska.gov — Alaska prejudgment interest (AS 09.30.070). https://public.courts.alaska.gov/web/forms/docs/adm-505.pdf. Government edict — not subject to copyright.
• Alabama — alison.legislature.state.al.us — Alabama judgment interest (Ala. Code § 8-8-10(a)). https://alison.legislature.state.al.us/code-of-alabama?section=8-8-10. Government edict — not subject to copyright.
• Alabama — alison.legislature.state.al.us — Alabama prejudgment interest (Ala. Code § 8-8-1). https://alison.legislature.state.al.us/code-of-alabama?section=8-8-1. Government edict — not subject to copyright.
• Arkansas — federalreserve.gov — Arkansas judgment interest (Ark. Code Ann. § 16-65-114(a)). https://www.federalreserve.gov/releases/h15/. Government edict — not subject to copyright.
• Arkansas — codes.findlaw.com — Arkansas prejudgment interest (Ark. Code Ann. § 16-65-114(a)(1)). https://codes.findlaw.com/ar/title-16-practice-procedure-and-courts/ar-code-sect-16-65-114/. Government edict — not subject to copyright.
• Arizona State Legislature (official) — Arizona judgment interest (A.R.S. §44-1201). https://www.azleg.gov/ars/44/01201.htm. Government edict — not subject to copyright.
• Arizona — azleg.gov — Arizona prejudgment interest (A.R.S. § 44-1201(A), &). https://www.azleg.gov/ars/44/01201.htm. Government edict — not subject to copyright.
• Bank of England — Bank of England — Bank Rate (IUDBEDR). https://www.bankofengland.co.uk/boeapps/database/Bank-Rate.asp. Bank of England statistical data, free to reuse with attribution.
• California Legislative Information (official) — California Code of Civil Procedure §685.010. https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=CCP&sectionNum=685.010. Government edict — not subject to copyright.
• California — leginfo.legislature.ca.gov — California prejudgment interest (Cal. Civ. Code sec. 3287). https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?sectionNum=3289.&lawCode=CIV. Government edict — not subject to copyright.
• Colorado — colorado.public.law — Colorado prejudgment interest (C.R.S. 5-12-102). https://colorado.public.law/statutes/crs_5-12-102. Government edict — not subject to copyright.
• Colorado Secretary of State (official rate certification) — Colorado judgment interest (C.R.S. §5-12-102 / §13-21-101). https://www.coloradosos.gov/pubs/info_center/files/interest_rates.pdf. Government edict — not subject to copyright.
• Connecticut — cga.ct.gov — Connecticut judgment interest (Conn. Gen. Stat. §37-3a). https://www.cga.ct.gov/current/pub/chap_673.htm. Government edict — not subject to copyright.
• Connecticut — portal.ct.gov — Connecticut prejudgment interest (Conn. Gen. Stat. § 37-3a(a)). https://portal.ct.gov/wcc/statutes-and-regulations/do-not-use-related-statutes/2021-related-statutes/37-3a. Government edict — not subject to copyright.
• District of Columbia — code.dccouncil.gov — District of Columbia judgment interest (D.C. Code § 28-3302(c)). https://code.dccouncil.gov/us/dc/council/code/sections/28-3302. Government edict — not subject to copyright.
• D.C. — code.dccouncil.gov — D.C. prejudgment interest (D.C. Code § 15-108). https://code.dccouncil.gov/us/dc/council/code/sections/15-108. Government edict — not subject to copyright.
• Delaware — delcode.delaware.gov — Delaware judgment interest (6 Del. C. § 2301). https://delcode.delaware.gov/title6/c023/. Government edict — not subject to copyright.
• Delaware — delcode.delaware.gov — Delaware prejudgment interest (6 Del. C. § 2301(a)). https://delcode.delaware.gov/title6/c023/. Government edict — not subject to copyright.
• European Central Bank — ECB — Main Refinancing Operations fixed rate (MRR). https://data.ecb.europa.eu/data/datasets/FM/FM.B.U2.EUR.4F.KR.MRR_FR.LEV. ECB statistical data, free to reuse with attribution.
• Board of Governors of the Federal Reserve System — Federal Reserve H.15 — 1-Year Treasury Constant Maturity. https://www.federalreserve.gov/releases/h15/. U.S. federal government work — public domain. Fed Data Download Program is a public bulk feed.
• Florida Chief Financial Officer (official) — Florida judgment interest rate (Fla. Stat. §55.03). https://myfloridacfo.com/division/aa/audits-reports/judgment-interest-rates. Government edict — not subject to copyright.
• Florida — myfloridacfo.com — Florida prejudgment interest (Fla. Stat. § 55.03). https://myfloridacfo.com/division/aa/audits-reports/judgment-interest-rates. Government edict — not subject to copyright.
• Official Code of Georgia Annotated — Georgia judgment interest (O.C.G.A. §7-4-12). http://ga.elaws.us/law/section7-4-12. Government edict — not subject to copyright.
• Georgia — ga.elaws.us — Georgia prejudgment interest (O.C.G.A. § 7-4-15). http://ga.elaws.us/law/section7-4-2. Government edict — not subject to copyright.
• Hawaii — capitol.hawaii.gov — Hawaii judgment interest (Haw. Rev. Stat. 478-3. Related: 478-2). https://www.capitol.hawaii.gov/hrscurrent/Vol11_Ch0476-0490/HRS0478/HRS_0478-0003.htm. Government edict — not subject to copyright.
• Hawaii — data.capitol.hawaii.gov — Hawaii prejudgment interest (HRS 636-16). https://data.capitol.hawaii.gov/sessions/session2017/HRS-Chapter-PDF's/HRS_0478.pdf. Government edict — not subject to copyright.
• Iowa Legislature (official) — Iowa Code §668.13. https://www.legis.iowa.gov/docs/code/668.13.pdf. Government edict — not subject to copyright.
• Iowa — legis.iowa.gov — Iowa prejudgment interest (Iowa Code § 668.13). https://www.legis.iowa.gov/docs/code/668.13.pdf. Government edict — not subject to copyright.
• Idaho — sto.idaho.gov — Idaho judgment interest (Idaho Code § 28-22-104(2)). https://sto.idaho.gov/Banking/Legal-Rate-of-Interest. Government edict — not subject to copyright.
• Idaho — legislature.idaho.gov — Idaho prejudgment interest (Idaho Code 28-22-104(1)). https://legislature.idaho.gov/statutesrules/idstat/title28/t28ch22/sect28-22-104/. Government edict — not subject to copyright.
• Illinois General Assembly (official) — Illinois judgment interest (735 ILCS 5/2-1303). https://www.ilga.gov/legislation/ilcs/fulltext?DocName=073500050K2-1303. Government edict — not subject to copyright.
• Illinois — ilga.gov — Illinois prejudgment interest (735 ILCS 5/2-1303(c)). https://ilga.gov/documents/legislation/ilcs/documents/081502050K2.htm. Government edict — not subject to copyright.
• Indiana — iga.in.gov — Indiana judgment interest (Ind. Code § 24-4.6-1-101). https://iga.in.gov/laws/2025/ic/titles/24. Government edict — not subject to copyright.
• Indiana — iga.in.gov — Indiana prejudgment interest (Contract/liquidated: IC 24-4.6-1-103). https://iga.in.gov/laws/2024/ic/titles/24#24-4.6-1-103. Government edict — not subject to copyright.
• U.S. Internal Revenue Service — IRS quarterly interest rates (§6621). https://www.irs.gov/payments/quarterly-interest-rates. U.S. federal government work — not subject to copyright (public domain).
• Kansas — sos.ks.gov — Kansas judgment interest (Kan. Stat. Ann. 16-204). https://sos.ks.gov/general-services/finance-rates.html. Government edict — not subject to copyright.
• Kansas — ksrevisor.gov — Kansas prejudgment interest (K.S.A. 16-201). https://ksrevisor.gov/statutes/chapters/ch16/016_002_0001.html. Government edict — not subject to copyright.
• Kentucky — apps.legislature.ky.gov — Kentucky judgment interest (KRS 360.040). https://apps.legislature.ky.gov/law/statutes/statute.aspx?id=45719. Government edict — not subject to copyright.
• Kentucky — apps.legislature.ky.gov — Kentucky prejudgment interest (KRS 360.010(1)). https://apps.legislature.ky.gov/law/statutes/statute.aspx?id=47989. Government edict — not subject to copyright.
• Louisiana — ofi.la.gov — Louisiana judgment interest (La. R.S. 13:4202(B)). https://ofi.la.gov/legal/statutes-rules-policies-opinions/judicial-interest-rates/. Government edict — not subject to copyright.
• Louisiana — ofi.la.gov — Louisiana prejudgment interest (La. R.S. 13:4202). https://ofi.la.gov/legal/statutes-rules-policies-opinions/judicial-interest-rates/. Government edict — not subject to copyright.
• Massachusetts Legislature (official) — Massachusetts G.L. c.231 §§6B–6C. https://malegislature.gov/Laws/GeneralLaws/PartIII/TitleII/Chapter231/Section6B. Government edict — not subject to copyright.
• Massachusetts — malegislature.gov — Massachusetts prejudgment interest (M.G.L. c. 231, § 6B). https://malegislature.gov/Laws/GeneralLaws/PartIII/TitleII/Chapter231/Section6B. Government edict — not subject to copyright.
• Maryland — mgaleg.maryland.gov — Maryland judgment interest (Md. Code, Courts & Judicial Proceedings Section 11-107(a)). https://mgaleg.maryland.gov/mgawebsite/laws/StatuteText?article=gcj&section=11-107. Government edict — not subject to copyright.
• Maryland — mgaleg.maryland.gov — Maryland prejudgment interest (Md. Const. Art. III, sec. 57). https://mgaleg.maryland.gov/Pubs/LegisLegal/2025-constitution-maryland-us.pdf. Government edict — not subject to copyright.
• Maine — legislature.maine.gov — Maine judgment interest (14 M.R.S. §1602-C). https://legislature.maine.gov/statutes/14/title14sec1602-C.html. Government edict — not subject to copyright.
• Maine — legislature.maine.gov — Maine prejudgment interest (14 M.R.S. § 1602-B). https://legislature.maine.gov/statutes/14/title14sec1602-B.html. Government edict — not subject to copyright.
• Michigan Legislature (official) — Michigan judgment interest (MCL §600.6013). https://www.legislature.mi.gov/Laws/MCL?objectName=mcl-600-6013. Government edict — not subject to copyright.
• Michigan — legislature.mi.gov — Michigan prejudgment interest (MCL 600.6013). https://www.legislature.mi.gov/Laws/MCL?objectName=mcl-600-6013. Government edict — not subject to copyright.
• Minnesota — revisor.mn.gov — Minnesota judgment interest (Minn. Stat. § 549.09, subd. 1(c)). https://www.revisor.mn.gov/court_rules/rule/msinte/. Government edict — not subject to copyright.
• Minnesota — revisor.mn.gov — Minnesota prejudgment interest (Minn. Stat. § 549.09, subd. 1(b)). https://www.revisor.mn.gov/statutes/cite/549.09. Government edict — not subject to copyright.
• Missouri — revisor.mo.gov — Missouri judgment interest (Mo. Rev. Stat. §408.040). https://revisor.mo.gov/main/OneSection.aspx?section=408.040. Government edict — not subject to copyright.
• Missouri — revisor.mo.gov — Missouri prejudgment interest (Mo. Rev. Stat. § 408.040). https://revisor.mo.gov/main/OneSection.aspx?section=408.040. Government edict — not subject to copyright.
• Mississippi — law.justia.com — Mississippi prejudgment interest (Miss. Code Ann. § 75-17-7). https://law.justia.com/codes/mississippi/title-75/chapter-17/general-provisions/section-75-17-7/. Government edict — not subject to copyright.
• Montana — mca.legmt.gov — Montana judgment interest (Mont. Code Ann. § 25-9-205). https://mca.legmt.gov/bills/mca/title_0250/chapter_0090/part_0020/section_0050/0250-0090-0020-0050.html. Government edict — not subject to copyright.
• Montana — mca.legmt.gov — Montana prejudgment interest (MCA 27-1-211). https://mca.legmt.gov/bills/mca/title_0270/chapter_0010/part_0020/section_0110/0270-0010-0020-0110.html. Government edict — not subject to copyright.
• North Carolina General Assembly (official) — North Carolina judgment interest (N.C.G.S. §24-5 / §24-1). https://www.ncleg.gov/EnactedLegislation/Statutes/HTML/BySection/Chapter_24/GS_24-5.html. Government edict — not subject to copyright.
• North Carolina — ncleg.net — North Carolina prejudgment interest (N.C. Gen. Stat. 24-5). https://www.ncleg.net/EnactedLegislation/Statutes/PDF/BySection/Chapter_24/GS_24-5.pdf. Government edict — not subject to copyright.
• North Dakota — ndcourts.gov — North Dakota judgment interest (N.D.C.C. § 28-20-34). https://www.ndcourts.gov/state-court-administration/interest-rate-on-judgments. Government edict — not subject to copyright.
• North Dakota — ndlegis.gov — North Dakota prejudgment interest (N.D.C.C. § 32-03-04). https://ndlegis.gov/cencode/t32c03.pdf. Government edict — not subject to copyright.
• Nebraska — nebraskajudicial.gov — Nebraska judgment interest (Neb. Rev. Stat. § 45-103). https://nebraskajudicial.gov/rules/administrative-policies-schedules/judgment-interest-rate. Government edict — not subject to copyright.
• Nebraska — nebraskalegislature.gov — Nebraska prejudgment interest (Neb. Rev. Stat. sec. 45-104). https://nebraskalegislature.gov/laws/statutes.php?statute=45-104. Government edict — not subject to copyright.
• New Hampshire — courts.nh.gov — New Hampshire judgment interest (N.H. Rev. Stat. Ann. 336:1, II). https://www.courts.nh.gov/our-courts/superior-court/civil/civil-interest-rates. Government edict — not subject to copyright.
• New Hampshire — courts.nh.gov — New Hampshire prejudgment interest (RSA 336:1, II). https://www.courts.nh.gov/our-courts/superior-court/civil/civil-interest-rates. Government edict — not subject to copyright.
• New Jersey Courts (official) — New Jersey post-judgment interest (R. 4:42-11). https://www.njcourts.gov/notices/notice-post-judgment-interest-rate-calendar-year-2026-rule-442-11. Government edict — not subject to copyright.
• New Jersey — njcourts.gov — New Jersey prejudgment interest (N.J. Ct. R. 4:42-11(b)). https://www.njcourts.gov/sites/default/files/courts/civil/postprejudgmentrates.pdf. Government edict — not subject to copyright.
• New Mexico — law.justia.com — New Mexico judgment interest (N.M. Stat. Ann. § 56-8-4). https://law.justia.com/codes/new-mexico/chapter-56/article-8/section-56-8-4/. Government edict — not subject to copyright.
• New Mexico — codes.findlaw.com — New Mexico prejudgment interest (NMSA 1978, Sec. 56-8-4(B)). https://codes.findlaw.com/nm/chapter-56-commercial-instruments-and-transactions/nm-st-sect-56-8-4/. Government edict — not subject to copyright.
• Nevada — fid.nv.gov — Nevada judgment interest (Nev. Rev. Stat. 17.130(2)). https://fid.nv.gov/uploadedFiles/fidnvgov/content/Resources/Prime%20Interest%20Rate%20July%201,%202026.pdf. Government edict — not subject to copyright.
• Nevada — leg.state.nv.us — Nevada prejudgment interest (NRS 99.040). https://www.leg.state.nv.us/NRS/NRS-099.html. Government edict — not subject to copyright.
• New York — nysenate.gov — New York prejudgment interest (N.Y. C.P.L.R. 5004). https://www.nysenate.gov/legislation/laws/CVP/5004. Government edict — not subject to copyright.
• New York State Senate (official statute text) — New York CPLR 5004. https://www.nysenate.gov/legislation/laws/CVP/5004. Government edict — not subject to copyright.
• Ohio — codes.ohio.gov — Ohio prejudgment interest (Ohio Rev. Code 1343.03). https://codes.ohio.gov/ohio-revised-code/section-1343.03. Government edict — not subject to copyright.
• Ohio Department of Taxation (official) — Ohio judgment interest (R.C. §1343.03 / §5703.47). https://tax.ohio.gov/individual/resources/annual-interest-rates. Government edict — not subject to copyright.
• Oklahoma — oscn.net — Oklahoma judgment interest (12 O.S. Sec. 727.1). https://www.oscn.net/applications/oscn/DeliverDocument.asp?CiteID=551111. Government edict — not subject to copyright.
• Oklahoma — oscn.net — Oklahoma prejudgment interest (12 O.S. Sec. 727.1). https://www.oscn.net/applications/oscn/DeliverDocument.asp?CiteID=551111. Government edict — not subject to copyright.
• Oregon — oregonlegislature.gov — Oregon judgment interest (ORS 82.010(2)). https://www.oregonlegislature.gov/bills_laws/ors/ors082.html. Government edict — not subject to copyright.
• Oregon — oregon.public.law — Oregon prejudgment interest (ORS 82.010(1)(a)). https://oregon.public.law/statutes/ors_82.010. Government edict — not subject to copyright.
• Pennsylvania — pacodeandbulletin.gov — Pennsylvania prejudgment interest (41 P.S. Sec. 202). https://www.pacodeandbulletin.gov/secure/pacode/data/231/chapter200/s238.html. Government edict — not subject to copyright.
• Pennsylvania General Assembly (official) — Pennsylvania judgment interest (42 Pa.C.S. §8101; 41 P.S. §202). https://www.legis.state.pa.us/WU01/LI/LI/CT/HTM/42/00.081.001.000..HTM. Government edict — not subject to copyright.
• Rhode Island — webserver.rilegislature.gov — Rhode Island judgment interest (R.I. Gen. Laws § 9-21-10). https://webserver.rilegislature.gov/Statutes/TITLE9/9-21/9-21-10.HTM. Government edict — not subject to copyright.
• Rhode Island — webserver.rilegislature.gov — Rhode Island prejudgment interest (R.I. Gen. Laws § 9-21-10). https://webserver.rilegislature.gov/Statutes/TITLE9/9-21/9-21-10.HTM. Government edict — not subject to copyright.
• South Carolina — scstatehouse.gov — South Carolina judgment interest (S.C. Code Ann. § 34-31-20(B)). https://www.scstatehouse.gov/code/t34c031.php. Government edict — not subject to copyright.
• South Carolina — scstatehouse.gov — South Carolina prejudgment interest (S.C. Code Ann. § 34-31-20(A)). https://www.scstatehouse.gov/code/t34c031.php. Government edict — not subject to copyright.
• South Dakota — sdlegislature.gov — South Dakota judgment interest (SDCL § 54-3-5.1). https://sdlegislature.gov/Statutes/54-3-5.1. Government edict — not subject to copyright.
• South Dakota — sdlegislature.gov — South Dakota prejudgment interest (SDCL 21-1-13.1). https://sdlegislature.gov/Statutes/21-1-13.1. Government edict — not subject to copyright.
• Tennessee Courts / Dept. of Financial Institutions (official) — Tennessee post-judgment interest (Tenn. Code §47-14-121). https://www.tncourts.gov/tennessee-judgment-interest-rates. Government edict — not subject to copyright.
• Tennessee — codes.findlaw.com — Tennessee prejudgment interest (Tenn. Code Ann. § 47-14-123). https://codes.findlaw.com/tn/title-47-commercial-instruments-and-transactions/tn-code-sect-47-14-123/. Government edict — not subject to copyright.
• Texas Office of Consumer Credit Commissioner (official) — Texas post-judgment interest rate (Fin. Code §304.003). https://occc.texas.gov/publications/interest-rates/. Government edict — not subject to copyright.
• Texas — statutes.capitol.texas.gov — Texas prejudgment interest (Tex. Fin. Code Sec. 304.102). https://statutes.capitol.texas.gov/Docs/FI/pdf/FI.304.pdf. Government edict — not subject to copyright.
• Utah — utcourts.gov — Utah judgment interest (Utah Code Ann. Sec. 15-1-4). https://www.utcourts.gov/en/court-records-publications/resources/interest-rates/interestrates.html. Government edict — not subject to copyright.
• Utah — le.utah.gov — Utah prejudgment interest (Utah Code Ann. 15-1-1(2)). https://le.utah.gov/xcode/Title15/Chapter1/15-1-S1.html. Government edict — not subject to copyright.
• Virginia General Assembly (official) — Virginia judgment interest (Va. Code §6.2-302). https://law.lis.virginia.gov/vacode/title6.2/chapter3/section6.2-302/. Government edict — not subject to copyright.
• Virginia — law.lis.virginia.gov — Virginia prejudgment interest (Va. Code Ann. § 8.01-382). https://law.lis.virginia.gov/vacode/title8.01/chapter13/section8.01-382/. Government edict — not subject to copyright.
• Vermont — legislature.vermont.gov — Vermont judgment interest (9 V.S.A. § 41a(a)). https://legislature.vermont.gov/statutes/section/09/004/00041a. Government edict — not subject to copyright.
• Vermont — legislature.vermont.gov — Vermont prejudgment interest (9 V.S.A. § 41a(a)). https://legislature.vermont.gov/statutes/section/09/004/00041a. Government edict — not subject to copyright.
• Washington — app.leg.wa.gov — Washington prejudgment interest (RCW 19.52.010(1)). https://app.leg.wa.gov/rcw/default.aspx?cite=19.52.010. Government edict — not subject to copyright.
• Washington State Legislature (official) — Washington post-judgment interest (RCW 4.56.110). https://app.leg.wa.gov/rcw/default.aspx?cite=4.56.110. Government edict — not subject to copyright.
• Wisconsin — docs.legis.wisconsin.gov — Wisconsin judgment interest (Wis. Stat. § 815.05(8)). https://docs.legis.wisconsin.gov/document/statutes/815.05(8. Government edict — not subject to copyright.
• Wisconsin — docs.legis.wisconsin.gov — Wisconsin prejudgment interest (Wis. Stat. 138.04). https://docs.legis.wisconsin.gov/statutes/statutes/138/04. Government edict — not subject to copyright.
• West Virginia — courtswv.gov — West Virginia judgment interest (W. Va. Code § 56-6-31). https://www.courtswv.gov/public-resources/news-publications/press-page/press-releases/supreme-court-sets-2026-interest-rate. Government edict — not subject to copyright.
• West Virginia — code.wvlegislature.gov — West Virginia prejudgment interest (W. Va. Code § 56-6-31(b)). https://code.wvlegislature.gov/56-6-31/. Government edict — not subject to copyright.
• Wyoming — wyoleg.gov — Wyoming judgment interest (Wyo. Stat. Ann. 1-16-102). https://wyoleg.gov/statutes/compress/title01.pdf. Government edict — not subject to copyright.
• Wyoming — wyoleg.gov — Wyoming prejudgment interest (Wyo. Stat. Ann. Sec. 40-14-106(e)). https://wyoleg.gov/statutes/compress/title40.pdf. Government edict — not subject to copyright.

US state judgment rates

State rates come in two kinds, and we treat them differently. Statute-fixed rates (California 10%, New York 9%/2%, Massachusetts 12%) are written into the law; we verify them against the official statute text (the legislature's own site), cite the section, record the carve-outs, and re-verify on a schedule — the page shows the verification date. Market-linked rates (Iowa: 1-yr Treasury + 2%) are computed weekly from the same official H.15 series as the federal rate, with the statutory formula cited.

US state prejudgment rates

Prejudgment interest — the interest that accrues before judgment, compensating for the time between the loss or breach and the judgment — is tracked as a separate metric from post-judgment interest, for all 50 states and D.C. (browse the table). It is treated differently for a reason: unlike the post-judgment rate, prejudgment interest usually turns on claim type. Most states allow it only on liquidated or readily ascertainable amounts and bar it on unliquidated damages (pain and suffering, most general tort damages); several make it discretionary; a few apply the same rate as post-judgment. Each state's page states the rate, the controlling statute or high-court rule, the accrual date, whether it is simple or compound, and the carve-outs — each verified against the official source on the date shown. Fixed statutory rates are high confidence; formula rates that reset off a benchmark are medium confidence and re-verified on a schedule.

Coverage & roadmap

The dataset covers U.S. federal statutory, judgment, and tax interest rates; U.S. state judgment rates (49 states + D.C. — every jurisdiction except Mississippi, which sets judgment interest case by case rather than by a fixed statutory default); U.S. state prejudgment interest rates (all 50 states + D.C.); U.K. statutory late-commercial-payment interest and the Bank of England base rate; and the EU Late Payment Directive reference rate and ECB main refinancing rate. Planned expansion: per-EU-country late-payment margins, and a prejudgment interest calculator.