TelosTax

Overview

TelosTax is a browser-based tax-preparation app for individuals filing a 2025 federal and state return. It is a strong fit for filers who value open-source software and an offline option; its narrow tax-year scope makes it a poor choice for other returns.

The project targets about 85–90% of individual filers with more than 90 tax features. Its federal coverage centers on Form 1040 and Schedules A–H, SE and D, plus more than 30 supplemental forms. It reports calculations for all 50 states and Washington, DC, and lists 41 IRS and 43 state PDF templates with field mapping to populate forms. That is a substantial stated range, but the coverage estimate is not a promise that every filer’s circumstances are supported.

Calculations are described as traceable to tax authorities including the Internal Revenue Code, Treasury Regulations, Revenue Procedures and IRS form instructions. That makes the project’s stated legal basis more inspectable, though it does not guarantee that a particular return is covered or correct.

Key features

Guidance, documents and deductions

TelosTax lists AI tax guidance, document import and deduction finding. Those features address common preparation tasks, but the AI capabilities are optional rather than built-in access to a service: BYOK Mode requires the user’s Anthropic API key. Users who do not want that dependency can choose Private Mode, which is described as fully offline.

Privacy and calculations

The project says it strips personally identifiable information before transmission in BYOK Mode and encrypts tax data at rest with AES-256-GCM. Its calculation layer is described as a standalone pure-function library with no database access or network calls. The repository reports more than 6,100 tests across 139 test files; that signals substantial test coverage, not a guarantee against errors.

Pricing

TelosTax is free and open source under the MIT license. Its Free plan costs nothing and covers tax preparation for tax year 2025. There is no paid tier to compare, but optional AI features require the user to supply an Anthropic API key. The project is from Telos News.

Platforms

TelosTax is available on Android, iOS, Linux, macOS, web and Windows. The repository describes it as installable on desktop and mobile and capable of offline use, giving privacy-conscious filers a way to work without relying on a continuously connected browser session.

Who it's for

Choose TelosTax if you file an individual 2025 return, want broad stated federal and state coverage, and value an open-source tool with an offline mode. It may also suit filers who want to inspect the stated legal basis for calculations. Look elsewhere if you need a tax year other than 2025, or if your situation falls outside the project’s intended coverage.

Pros and cons

• Pros: Free, MIT-licensed software gives individual filers access to a substantial stated 2025 form range without a subscription price.
• Pros: An offline Private Mode and stated encryption at rest are meaningful options for users who prioritize control over tax data.
• Pros: Federal forms, all-state calculations and mapped PDF templates make the stated coverage broader than a federal-only preparation tool.
• Cons: Federal support is specified for tax year 2025, limiting its usefulness for other filing years.
• Cons: AI features in BYOK Mode depend on the user providing an Anthropic API key, which adds setup and account requirements.
• Cons: The 85–90% filer coverage target leaves room for unsupported situations; filers with unusual needs should verify fit before relying on it.

Alternatives

Browse more options in AI Tax Software.

• H&R Block Online is worth considering for a simple Form 1040 return if you prefer a free online plan, though state filing is billed per state and the free option is limited to simple situations.
• Taxfix is an alternative for an individual return on Android, iOS or web, with its Basic annual plan at €39.99 a year and free until submission.
• Quicko may suit users seeking a freemium option across web and mobile; its Basic plan is free and is capped at ₹12 lakh total income and one app connection.
• TaxAct offers free federal filing for eligible standard returns, with state filing additional, making it an option for filers whose needs fit that narrower eligibility.
• TurboTax has a free edition for simple Form 1040 returns, including federal and state filing at $0 for eligible users.
• Instead is another freemium alternative with a free platform plan for unlimited users and entities.
• Taxation.ai offers a free plan with one federal return per year, five document uploads and a basic AI assistant and deduction finder.
• EZTax is a freemium alternative available on Android, iOS, web and Windows.

Verdict

TelosTax is best for individual filers preparing a 2025 return who want free, open-source software with offline capability and wide stated federal and state coverage. Its strongest reason to choose it is that combination of breadth and user control; its clearest reason to look elsewhere is the 2025-only federal scope, alongside uncertainty about fit for returns beyond its intended coverage.