Bizora is the tax research API that AI agents call.
When a user asks an agent a tax question, the agent calls Bizora and gets back an answer grounded in primary law, with every source cited. It covers federal tax, all 50 states, the US treaty network and audit standards. CPA firms use the same engine through our web app.
Listed in Claude's connector directory and the ChatGPT app directory. Try a question on the right to see what an agent gets back.
User asks the agentI moved to California in March. My RSUs vested in June while I was still on a Washington payroll. Does California tax them?
bizora.tax_research( query: "CA resident, RSU vest, WA employer, part year", mode: "deep_research", jurisdictions: ["CA", "WA", "US"] )
Yes. California taxes residents on income from all sources, so a June vest after you became a resident is California income wherever the employer sits. Washington has no wage income tax, so there is no other state credit to claim.
If any part of the grant period overlaps your nonresident months, that portion is allocated by workdays.
- Cal. Rev. & Tax. Code §17041, tax on residents
- FTB Publication 1100, nonresidents and part year residents
- FTB Publication 1004, equity compensation allocation
User asks the agentA private client's workpapers still cite ASC 605 for revenue. Is that still valid?
bizora.audit_research( query: "ASC 605 applicability, private entity", mode: "auto", standards: ["FASB ASC", "AICPA"] )
No. ASC 605 is superseded. ASC 606 applies to private companies for annual periods beginning after December 15, 2018, so each revenue stream should be mapped through the five step model.
The old guidance stays searchable for restatements and litigation support, and is always labeled as superseded.
- FASB ASC 606, Revenue from Contracts with Customers
- FASB ASC 605, superseded
User asks the agentOur US subsidiary pays royalties to its UK parent. What withholding applies?
bizora.tax_research( query: "US source royalties to UK parent, treaty rate", mode: "deep_research", jurisdictions: ["US", "GB"] )
Under the United States and United Kingdom income tax treaty, royalties beneficially owned by a UK resident are taxable only in the UK, so US withholding drops to zero.
The parent has to qualify under the limitation on benefits article, and the subsidiary needs valid treaty documentation before it pays.
- US and UK Income Tax Treaty, Article 12, Royalties
- US and UK Income Tax Treaty, Article 23, Limitation on Benefits
- IRC §1442, withholding on foreign corporations
Who uses Bizora
CPA firms of every size, in house tax teams and the software companies that serve them. We grew without paid acquisition.
| Top 25 | A Top 25 US CPA firm runs Bizora across the firmTheir internal AI model calls the Bizora API for tax research |
| Top 200 | Firms from the Top 200 use Bizora day to dayAlongside small practices, enrolled agents and in house tax teams |
| 1,000+ | Tax professionals on the platformCPAs, enrolled agents and corporate tax staff |
| 2 | Frontier AI directories list BizoraClaude's connector directory and the ChatGPT app directory |
What practitioners say
From CPAs and enrolled agents who use Bizora in their practices, as published on bizora.ai.
I love that responses cite primary sources and aren't summaries of summaries.
Bizora AI has become an invaluable research tool in my tax and accounting practice.
Bizora has been a great tool for us and can really dive deep in complicated tax questions.
Why now
Tax questions are moving out of research databases and into AI assistants. Those assistants need a source of law they can call.
- Agents are the new interface
Claude and ChatGPT now let users add connectors, and accounting software is shipping its own assistants. Tax questions increasingly start there. Bizora is already listed in both directories and runs inside partner products.
- A general model is not a source of law
Models answer from training data that can be years old. They can't reliably cite this year's rule or a specific state's version of it, and a practitioner can't sign off on an answer without a source.
- The law never stops changing
Federal rules, 50 state codes, treaties and audit standards each change on their own schedule. Every product that touches tax needs that maintained, and very few want to build it themselves.
From stealth to a Top 25 firm in one quarter
We ship a release every month and build what customers ask for.
- June 2026
Out of stealth
Launches publicly with 1,000+ users, all from word of mouth.
- August 2026
Audit Research launches
GAAP, IFRS, GASB, PCAOB, AICPA, SEC and Yellow Book, routed automatically alongside tax. Launch post
- September 2026
Listed in Claude and ChatGPT
Approved in Claude's connector directory and the ChatGPT app directory.
- Q3 2026
Top 25 firm goes live
Their internal AI model goes live on the Bizora API across the firm. Our first accounting software partners integrate.
- October 2026
Claude for Startups
Accepted into Anthropic's startup program.
- November 2026Upcoming
SOC 2 report
Independent attestation of our security controls.
- December 2026Upcoming
G20 coverage
Outbound cross border research across the G20, then global coverage in 2027.
What we built
One research engine with several ways in. Tax and audit questions are routed automatically, so integrations don't change as coverage grows.
API and MCP server
An OpenAI compatible /chat/completions endpoint and a hosted MCP server with OAuth. Agents pick fast or deep research, send structured JSON and get structured JSON back, with simple usage based pricing.
A firm can send a full tax return as JSON and get back structured findings its own models can act on.
Web app
Cited research for practitioners, with plans for solo preparers up to whole firms.
Return review
Upload a return with its W2s, 1099s and K1s. Bizora checks each source document against what was reported and flags mismatches.
Vault
Firms upload their own memos, SOPs and manuals and research against them alongside primary law.
Canvas
Turns research into client memos and position papers in the firm's own format.
Skills library
Nine free Claude skills built on our MCP, including 1040 review, K1 tie out and IRS notice response. Library
Advisory Group
White labeled review by credentialed professionals for platforms that need a licensed sign off.
What sits under every answer
A fluent answer is easy to generate. A professional needs it tied to the law in force, for the right year and jurisdiction. These are the parts of Bizora that make that possible.
- Primary source library
The Code, regulations, rulings, case law, state statutes, treaties and audit standards, collected and maintained by our team.
- Every year on record
Rules and form instructions are kept by year, so a 2023 question is answered under 2023 law.
- Authority awareness
Retrieval knows which authority controls a question, and labels superseded guidance instead of serving it as current.
- Measured before release
An evaluation set built from real practitioner questions scores accuracy and citations before each monthly release ships.
- Built for other software
Structured JSON in and out, automatic routing between tax and audit questions, and OAuth for MCP clients.
- Licensed professionals
Credentialed CPAs and EAs in our Advisory Group can review and sign off when a platform needs a human on the answer.
Coverage and accuracy
What Bizora covers today, and what comes next.
| Source set | Status |
|---|---|
| Federal taxCode, regulations, rulings and form instructions by year | Live |
| All 50 statesIncome, sales and property tax, residency and allocation | Live |
| US treaty networkInbound transactions and treaty positions | Live |
| Audit and accountingGAAP, IFRS, GASB, PCAOB, AICPA, SEC, GAO, FAR, IAASB | Live |
| Case lawUS Tax Court first, then federal and state courts | Live |
| G20 countriesOutbound cross border research | December 2026 |
| 200+ jurisdictionsGlobal coverage | 2027 |
- Every answer cites the primary source it rests on
- Zero data retention available for enterprise
- SOC 2 audit underway
Where firms already find us
We sell to CPA firms directly and through the software they already use. Each integration puts Bizora in front of new firms without a new sales cycle.
AI platforms
- Claude
- Official connector in the directory. Connection guide
- ChatGPT
- Live in the app directory
- Any MCP client
- Claude Code, Cursor and others connect with OAuth or an API key
Accounting software on our API
- Truss
- Bizora research inside Max AI, the assistant in Truss's tax workflow platform. CPA Practice Advisor
- AI tax prep
- Quality checks on completed returns before filing
- White label
- Our research engine under a partner's own brand
The profession
- Information Technology Alliance
- Technology Partner since September 2026. Announcement
- State CPA societies
- CalCPA, PSTAP, NYSSEA, TXSEA and MassCPAs
- Bizora Brews
- Our podcast with firm partners and heads of tax
- Bizora Impact
- Free access for students at USC, SJSU, Cornell and Santa Clara. Program
Bizora moved the fastest and provided the best depth and quality in any potential integration.
In the press
Independent coverage from the accounting trade press and Adam's alma mater.
| October 7, 2026 | CPA Practice Advisor | Bizora Tax Research Now Available Inside Truss |
| September 14, 2026 | CPA Practice Advisor | Bizora Joins the Information Technology Alliance as a Showcase Technology Partner |
| July 24, 2026 | Accounting Today | Tech News: Bizora announces advisory group |
| May 4, 2026 | Pulse 2.0 | Interview with founder and CEO Adam Tahir |
| July 22, 2025 | Cal State Fullerton News | CSUF Business Grad Launches AI Fintech Startup |
| June 17, 2025 | Accounting Today | Beyond algorithms, human judgment defines the future of accounting, by Adam Tahir |
What this means for YC companies
Payroll, payments, bookkeeping, commerce and wealth products all end up answering tax questions. Their agents can call Bizora instead of guessing.
| Payroll and HRRemote teams, multistate withholding, equity | Which state withholds for an employee who lives in New Jersey and works from Pennsylvania? |
| Accounting and financeClose, audit support, tax provision | Do we have to capitalize this year's software development costs under §174? |
| CommerceSales tax and nexus | We sold $480,000 into Texas this year. Do we have nexus? |
| Wealth and fintechClient planning, cross border | How is a UK pension distribution taxed for a US resident client? |
Where this goes
Every country has its own tax law, and every agent will need it. Global coverage makes Bizora the one source they all call.
When anyone asks an AI model a tax question, anywhere in the world, we want the model to call Bizora for the answer.
- Today
US tax and audit
Federal, 50 states, treaty network and audit standards, for firms and software.
- December 2026
G20
Cross border research for the largest economies.
- 2027
200+ jurisdictions
Global coverage for agents, model providers and platforms.
Team
A CPA who spent six years answering these questions by hand, and an engineer who has built and sold AI infrastructure before.
Adam Tahir
Cofounder and CEO
Licensed CPA. Six years in international transaction tax at EY, serving tech and entertainment clients. Speaks on IRC §7216 and AI for CalCPA, PSTAP, WSCPA and CPAacademy.
Kiran Patil
Cofounder and CTO
Built an AI platform that IBM acquired, an AI workforce scheduling system at scale, and enterprise security infrastructure.
Adam and Kiran met through YC cofounder matching.
Talk to us
If you're a YC partner reviewing our application, or a founder whose product needs tax answers, Adam would like to hear from you.