TelosTax review
Free, open-source tax preparation with offline calculations and optional API-key AI tools.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
For individual filers preparing a 2025 US federal and state return, TelosTax is a free, open-source tax preparation app. It supports Form 1040, schedules, and supplemental forms, and calculates income taxes for all 50 states and DC. Its documented coverage includes income types, deductions, credits, capital gains, alternative minimum tax, penalties, and depreciation. The project also says the tax calculation engine is open source, giving privacy-minded filers a locally oriented option without a subscription price.
Privacy and AI are the product’s defining trade-off. In offline private mode, calculations run client-side. Optional AI chat, expense scanning, and document extraction use the filer’s own Anthropic API key, so the AI features are not presented as an included service. This setup may suit someone who wants to keep calculations local and selectively add AI tools; it is less suitable for a buyer seeking an all-in-one service with AI access bundled into the product. TelosTax is available across web, desktop, and mobile platforms, with listed support for Windows, macOS, Linux, iOS, and Android.
The workflow ends with populated IRS and state PDF forms. The repository describes form preparation, but does not document electronic filing or expert review, so filers who want a guided filing-and-submission service or access to a tax professional should consider another option. TelosTax is a stronger fit for solo filers comfortable reviewing prepared forms and handling the next steps themselves. Its broad documented calculation coverage is useful for varied personal tax situations, while the individual-return focus makes it a poor match for business tax preparation.
TelosTax pros and cons
- Where it wins
- Calculates federal and state income taxes for all 50 states and DC
- Offline private mode runs calculations client-side
- Creates populated IRS and state PDF forms
- Where it doesn't
- AI tools require the user's Anthropic API key
- Focuses on individual returns
- No electronic filing or expert review is documented
TelosTax fact sheet, pricing and score →
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