You choose where the documents live
Run the practice in the cloud on an isolated tenant with firm-held recovery keys, or keep documents entirely on your own Mac and iPhone with the on-device apps. Same tax engine either way.
Taxes done by AI. Priced like it.
File your own return on your Mac or iPhone, or run an entire practice in the cloud. The AI does the work that used to bill by the hour — and on Tesseract-Tax your documents never leave your device at all.
Authorized IRS e-file Provider · 1040, 1065, 1120 and 1120-S · zero data retention
A tesseract is a cube in four dimensions. Get a four-dimensional view of your taxes — collect, extract, estimate, file.
Capitol Camera · U.S. Senate
Our Tax Products
One family of tax intelligence — cloud for firms, on-device for individuals and businesses.
Tesseract Tax CloudNew
The agentic tax platform for CPA firms, their clients, and individual filers — AI document extraction, live estimates with cited research, e-signatures, and accounting connectors. Live at platform.knottheory.ai, with native iOS and Android apps.
Tesseract-Tax™
Tax document collector for macOS and iOS — now supporting 8 countries. Scan, import, and organize tax forms with on-device extraction, AI chat, and country-specific tax estimation.
Tesseract-CorpTax
Corporate tax organizer for S-Corps, C-Corps, and LLCs — entity-aware document collection, extraction, and estimation that runs on your own hardware, not ours.
01 / The product
One engine. Two deployments.
Your firm is the system of record.
Tesseract gives CPAs the leverage of tax AI without turning their clients’ financial lives into someone else’s training data. Every engagement sits in your own isolated tenant, encrypted with recovery keys your firm holds — and the AI that reads the documents is run in zero-retention mode, so nothing you upload is stored or learned from.
The privacy boundary
Your tenant by default.
Vendors by exception.
Tax software should make the boundary obvious. This is what stays inside your tenant — and the two moments something deliberately crosses it.
Inside your tenant
- 01Client documentsEncrypted, recovery keys held by your firm
- 02Review + workpapersPer-tenant isolation
- 03Estimates + researchEvery number traced to its source
- 04CPA approvalYour firm signs off
Crossed on purpose
AI extraction
Documents are read by Anthropic Claude models on Amazon Bedrock, configured for zero data retention — not stored, not logged, never training data.
Zero retentionIRS e-file
Once your firm approves the return, the filing package is transmitted to the IRS. Acknowledgments come back to the engagement.
Approved returns onlyPrefer no upload at all? Tesseract-Tax and Tesseract-CorpTax run the same extraction entirely on your own Mac or iPhone, where documents never leave the device.
02 / Why firms switch
Cloud tenant or on-device
AI that shows its work
Every extracted field links back to the box it came from. Every estimate carries a readable calculation trail and research cited to primary authority — the Code, the regulations, the rulings.
Cloud only where filing requires it
A return has to reach the IRS somehow. Once your firm approves it, the filing package is transmitted directly through Modernized e-File and the acknowledgment comes back to the engagement.
The firm workflow
From shoebox to acknowledgment.
One surface for intake, extraction, review, signature and filing — a four-dimensional view of a return, from the first document to the IRS accepting it.
Collect
Clients upload through the portal or email documents straight into the engagement. W-2s, 1099s, K-1s, brokerage statements and 20+ other form types.
Extract + review
The AI identifies each form, maps every box, flags what disagrees, and builds a federal and state estimate you can read line by line.
Approve
Your team resolves the exceptions, applies overrides, and captures the client's e-signature on Form 8879 — with the paid-preparer block filled in.
E-file
The approved return is transmitted to the IRS for Forms 1040, 1065, 1120 and 1120-S. Acknowledgments return to the engagement.
Why KnotTheory for Tax?
Tax documents are the most sensitive files you own. We treat them that way.
Privacy by Architecture
On-device apps never upload your documents. Cloud AI processing runs with zero data retention — never stored, never used for training. Your financials stay yours.
Agentic Extraction
W-2s, 1099s, K-1s, brokerage statements — our AI reads the form the way a preparer does: spatially, field by field, with the tax code in mind.
Built for the Full Return
From document collection to live estimates with cited research to e-signatures — through direct e-file with the IRS. KnotTheory.ai Inc. is an Authorized IRS e-file Provider.
Complex Taxes, Simple Price
AI does the heavy lifting that traditional prep bills by the hour. Multi-state moves, K-1s, stock compensation, side businesses — complicated tax situations handled for a fraction of what they used to cost.
Where we stand
Designed around the owner-CPA.
Small enough to talk to the people who build it. Authorized to file with the IRS.
- 4Federal return types filed directly
- 1040, 1065, 1120 and 1120-S
- 20+Tax document types extracted
- W-2, the 1099 series, K-1, 1098, brokerage statements
- 0Documents retained by AI processors
- Zero-data-retention mode, never training data
- 8Countries supported on-device
- Tesseract-Tax for macOS and iOS
30-day free trial
Start with one firm.
One workflow.
One real return.
We will set up a representative engagement, walk the privacy boundary with you, and give your team a tenant to test in before there is any conversation about firm pricing.
- 01Map your workflow
- 02Set up your firm's tenant
- 03Walk a real return with the product team
Questions
Clear answers before client data enters the room.
The things firms ask on the first call, answered before you have to make it.
Where do our clients' documents actually live?
In an isolated tenant belonging to your firm. Documents are encrypted at rest, and the recovery keys are held by the firm rather than by us. Nothing is shared across tenants.
What happens when the AI reads a document?
Extraction is performed by Anthropic Claude models running on Amazon Bedrock under our agreements with those providers, configured for zero data retention: your content is not stored, not logged, and never used to train models. They act as our processors and are contractually bound to protect your data to at least the standard set in our privacy policy.
Can we keep documents out of the cloud entirely?
Yes. Tesseract-Tax and Tesseract-CorpTax run the same extraction on your own Mac or iPhone, where documents, credentials and financial data never leave the device. Firms often use the on-device apps for the clients who will not upload anything, and the platform for everyone else.
Which returns can you e-file?
KnotTheory.ai Inc. is an Authorized IRS e-file Provider. Tesseract Tax Cloud transmits Forms 1040, 1065, 1120 and 1120-S directly to the IRS, with a compliant paid-preparer block on every signed return.
Can a small firm use this without an IT department?
That is the design goal. The platform is hosted, so there is nothing to install or patch. Sign in with Google, Apple, Microsoft or GitHub, or use a passkey, and add the rest of the practice from there.
How does the free trial work?
Thirty days, for CPA firms and individual filers alike, at platform.knottheory.ai. Book a demo first if you would rather be walked through a return that looks like your own work.
Get in Touch
CPA firm, individual filer, or questions about our apps — we’d love to hear from you.