Overview

TelosTax is a free, open-source tax preparation app for individual filers working on 2025 returns. It is best for people who value offline use and want calculations they can trace to tax authorities. Its central limitation is the year-specific scope: it should not be the choice for a return outside 2025.

The project aims to cover about 85–90% of individual filers with more than 90 tax features. Its federal scope includes Form 1040, Schedules A–H, SE and D, and more than 30 supplemental forms; it also reports calculations for all 50 states and Washington, DC. That breadth is useful, but the coverage estimate is a target, not a guarantee that a particular return is supported.

TelosTax pairs calculations with IRS and state PDF templates and says its computations can be traced to tax law and IRS instructions. That focus gives careful filers a way to examine how calculations are grounded, though it does not remove the need to confirm that their forms and circumstances fit the stated scope.

Key features

Guidance, documents and deductions

AI tax guidance, document import and deduction finding address three routine parts of preparation: getting help with tax questions, bringing in paperwork and identifying potential deductions. These features give the app more reach than a calculation-only tool, but AI assistance is optional and requires the user's own Anthropic API key. That makes it a less convenient fit for someone who expects built-in AI access without configuring a separate service.

Forms and calculation traceability

TelosTax lists 41 IRS PDF templates and 43 state templates with auto-populated field mapping. The project says its calculations trace to the Internal Revenue Code, Treasury Regulations, Revenue Procedures or IRS form instructions. This is a meaningful emphasis for users who want to inspect the basis of a result rather than treat it as a black box. It should not be mistaken for assurance that every return type is covered.

Privacy and offline use

Private Mode is described as fully offline. For users who want to keep preparation on their own device, that is a clear advantage; the calculation layer is described as a standalone library with no database access or network calls. Optional BYOK Mode sends AI requests through the user's Anthropic API key, with personally identifiable information stripped before transmission. TelosTax also states that tax data is encrypted at rest with AES-256-GCM. The app is described as installable on desktop and mobile as well as usable in a browser, which supports its offline-capable positioning.

Pricing

The Free plan is free and is described as a free, open-source tax preparation app for tax year 2025. It includes the stated federal and state calculation coverage, guidance and deduction-finding features, and document import. No paid tier is described, so there is no published upgrade path to compare; optional AI functions do require the user's own Anthropic API key. For an individual with a supported 2025 return, free access and an MIT-licensed project make this a low-cost option. The trade-off is that the scope is explicitly year-bound, and its broad coverage target may not fit every taxpayer.

Platforms

TelosTax is available on Android, iOS, Linux, macOS, the web and Windows. That range suits people switching between a browser and desktop or mobile devices, while its offline-capable, installable app description is particularly relevant to users who prefer not to prepare a return entirely online.

Who it's for

TelosTax is a sensible candidate for individual filers preparing a 2025 return whose forms fall within its stated federal and state scope, especially those who value open-source software, offline operation and traceable calculations. It is a poor fit for anyone filing another tax year or whose situation depends on forms or circumstances beyond the reported coverage. The project reports more than 6,100 tests across 139 test files, a substantial testing effort that supports its engineering approach but does not establish coverage for an individual return.

Pros and cons

Pros: Free and MIT-licensed, with desktop, mobile and browser availability, making it accessible across common devices.
Pros: Reported calculations for all 50 states and Washington, DC, plus a substantial set of federal schedules and supplemental forms, giving eligible 2025 filers broad stated coverage.
Pros: Offline Private Mode and a calculation layer described as free of network calls make local use a central strength.
Pros: Legal traceability and mapped IRS and state PDF templates offer useful transparency around calculations and form output.
Cons: Federal support is specified for 2025, excluding people preparing returns for other years.
Cons: AI features depend on the user's Anthropic API key, adding setup and an external service requirement.
Cons: The 85–90% coverage figure is an estimate of intended reach, not a promise that a complex or unusual return is supported.

Alternatives

For a different AI-focused option, AI Tax Software collects alternatives in the category. Taxation.ai is worth considering if a free plan with one federal return per year, five document uploads and community support better matches your needs. Choose EZTax instead if you need its stated Android, iOS, web and Windows availability or its self-service ITR filing plan at 249.00 INR per month.

Instead may suit users who need multi-entity work, collaborators or unlimited users and entities on its free platform rather than individual tax preparation. TaxAct is an alternative for eligible standard returns where free federal filing matters and paying extra for state filing is acceptable. H&R Block Online is another option for simple Form 1040 situations, with its free online plan billed per state filed.

Consider Keeper if expense discovery, deduction summaries and a 24/7 AI tax assistant are the priority. TurboTax offers a free edition for eligible simple Form 1040 returns with federal and state filing shown at $0. Quicko may be a better fit for users seeking an India-focused free plan capped at ₹12 lakh total income and one app connection.

Verdict

Choose TelosTax if you are an individual filer preparing a 2025 return within its stated coverage and want free, open-source software with an offline mode and traceable calculations. Its breadth and privacy-oriented options are compelling for that audience. Look elsewhere if you need a different tax year, require assured support for a particular return, or want AI assistance without supplying your own Anthropic API key.

	TaxFile	TelosTax
Free plan	No	Yes
Paid from	$3.25/mo	Free
Platforms	Web	Android, iOS, Linux, macOS, Web, Windows
Free plan	No	Yes
Business entity support	Sole proprietors; single-member LLCs
Federal e-file	Yes
State e-file	Yes
Included state returns	1 returns
Taxpayer types		personal
AI tax guidance		Yes
Document import		Yes
Deduction finding		Yes
Filing support		both

TaxFile vs TelosTax

TaxFile

TelosTax