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14,448 startups · 29 programs

Rational

Active · First Zero-human Accounting Firm

WebsiteYC profile

Why it ranks

How the rank works
9signal of 100 · rising 9
  • went through YCProgram · this site+4
  • team of 2Team size · YC's directory+2.5
  • hiringHiring · Titles (titles.fru.dev), YC+2

A sum of public facts, not a judgement and not investment advice.

Competitors

AICifratoShared: accounting firm, filing, operationsYC W25BogotáStartup →AIBearShared: accounting firm, finance, filingYC S26HelsinkiStartup →AISorabanShared: accounting firm, clientYC W21TempeStartup →AIBalanceShared: accounting firm, bookYC W26LondonStartup →AIBillow AI LabsShared: accounting firm, financeYC S26San FranciscoStartup →
Companies closest to Rational
Company
CifratoShared: accounting firm, filing, operationsYC W25ActiveAI
BearShared: accounting firm, finance, filingYC S26ActiveAI
SorabanShared: accounting firm, clientYC W21ActiveAI
BalanceShared: accounting firm, bookYC W26ActiveAI
Billow AI LabsShared: accounting firm, financeYC S26ActiveAI

Adjacent

AIKintowShared: accounting firm, bookspeedrun SR005New YorkStartup →AIFinlensShared: accounting firm, finance, bookYC W20San FranciscoStartup →OtherRecharglyShared: accounting firm, costAntler 2020AustraliaStartup →AIQuantoShared: accounting firmspeedrun SR006San FranciscoStartup →AILuca IQShared: accounting firm, irs, filingYC S26San FranciscoStartup →
Companies next to Rational
Company
KintowShared: accounting firm, bookspeedrun SR005Not statedAI
FinlensShared: accounting firm, finance, bookYC W20ActiveAI
RecharglyShared: accounting firm, costAntler 2020Not statedOther
QuantoShared: accounting firmspeedrun SR006Not statedAI
Luca IQShared: accounting firm, irs, filingYC S26ActiveAI, Devtools

Also from S26 in AI

All of S26
AIAudunAI-native debt collection companyYC S26OsloStartup →AIComputableDerivatives Exchange for ComputeYC S26New York CityStartup →AILevocred AIAI Workforce for lendersYC S26San FranciscoStartup →AINebuSecAutonomous AI defense system for cyber attackYC S26San FranciscoStartup →AIProdigy ResearchTraining the world's best AI model for quantitative finance.YC S26San FranciscoStartup →AIRapidfolioAI-native back-office for banks and fintechsYC S26San FranciscoStartup →
Company
AudunAI-native debt collection companyteam of 5hiringActiveAI
ComputableDerivatives Exchange for Computeteam of 2ActiveAI, Devtools
Levocred AIAI Workforce for lendersteam of 2ActiveAI
NebuSecAutonomous AI defense system for cyber attackteam of 4ActiveAI
Prodigy ResearchTraining the world's best AI model for quantitative finance.team of 2ActiveAI
RapidfolioAI-native back-office for banks and fintechsActiveAI

Founders

  • Jibril MoinuddinFounder/CEO
  • Christ XuFounder/CTO

About Rational

Rational is building the first accounting firm with no humans. It's entirely run by our AI employees, who go from client intake to doing the books to filing with the IRS. We secure 90% cost reduction, 24/7 support, and an overall seamless experience for businesses.

YC batch
S26 · Summer 2026
Status, per YC
Active
Category
AI
Team size
2
Location
San Francisco, CA, USA
Founded
2026
Checked
6h ago

YC tags: Finance, B2B, Enterprise, AI

Changes seen

TagsOct 19, 2026

Newly tagged AI; no longer tagged Artificial Intelligence.

Source ↗

Rational in S26: 229 companies, 88% AI

LinkedIn

Rational: questions

Which YC batch was Rational in?

Rational was in Y Combinator's Summer 2026 batch (S26).

Is Rational still active?

Y Combinator lists Rational as active.

Who founded Rational?

Rational's founders, as listed on its YC page: Jibril Moinuddin (Founder/CEO), Christ Xu (Founder/CTO).

Where is Rational based?

Rational lists San Francisco, CA, USA as its location on YC's directory.