Overview

TelosTax is a browser-based tax-preparation app for individual taxpayers. It suits filers who want an open-source option with an offline mode and are preparing a 2025 return. Its strongest case is the combination of broad stated form coverage and a calculation engine designed to work without network access; its year-specific scope is a firm boundary.

The project describes more than 90 tax features intended to cover about 85–90% of individual filers. Federal support centers on Form 1040, Schedules A–H, SE and D, plus more than 30 supplemental forms. It reports calculations for all 50 states and Washington, DC, but its published scope specifies federal support for tax year 2025. That makes it a poor fit for anyone preparing a return for a different year, and the coverage estimate is not a guarantee that a particular return is supported.

TelosTax lists 41 IRS PDF templates and 43 state templates with field mapping to populate forms. The project also says calculations can be traced to the Internal Revenue Code, Treasury Regulations, Revenue Procedures or IRS form instructions. Those features give users a way to inspect the intended basis and output of a calculation, rather than treating the result as a black box.

Key features

Guidance, documents and deductions

AI tax guidance, document import and deduction finding address practical parts of preparing a return: getting help with tax questions, bringing in paperwork and identifying possible deductions. These are useful additions for filers who want assistance within the preparation workflow, but the stated 2025 scope still determines whether the app fits their return.

Offline privacy and optional AI

Private Mode is described as fully offline, a meaningful choice for users who do not want tax preparation to depend on a network connection. The calculation layer is a standalone pure-function library with no database access or network calls. TelosTax also states that tax data is encrypted at rest with AES-256-GCM.

AI functions are optional and use the taxpayer’s own Anthropic API key for chat, expense scanning and document extraction. The project says personally identifiable information is stripped before transmission. This arrangement gives privacy-conscious users a way to keep AI out of the workflow, while those who want the AI tools must supply a key and accept that the functions transmit data after the stated stripping step.

Forms and calculation scope

The reported state coverage and extensive form set make TelosTax more substantial than a basic calculator, while the legal traceability emphasis may matter to users who want to follow how a result is grounded. The repository reports more than 6,100 tests across 139 test files. That is evidence of a sizeable testing effort, not a promise that every filer’s circumstances are handled.

Pricing

The Free plan is free and is described as a free, open-source tax-preparation app for tax year 2025. It includes the app’s stated personal-tax scope and its listed AI guidance and deduction-finding features. No paid plan is described; the maker does not publish plan prices on its site, so there is no priced upgrade to compare. Users who want optional AI functions also need their own Anthropic API key.

This is a straightforward fit for an individual who wants to prepare a 2025 return without paying a stated subscription price. The trade-off is not a cheaper tier with fewer features, but the constraints of the product itself: 2025 federal support, a stated target rather than guaranteed coverage, and a user-supplied key for AI functions.

Platforms

TelosTax is browser-based and lists Android, iOS, Linux, macOS, web and Windows support. The repository describes it as installable on desktop and mobile and offline-capable. That combination suits users who want a browser workflow with the option to install the app and use Private Mode offline.

Who it's for

TelosTax is best for individual filers preparing a 2025 return who value open-source software, offline use or traceable calculations. It is also a reasonable option for users whose needs fall within the listed 1040 schedules, supplemental forms and state calculation coverage. Anyone filing for another federal tax year, or whose circumstances fall outside the stated target coverage, should choose a product whose scope matches the return.

Pros and cons

Pros: A free, open-source app with a wide stated set of federal forms and calculations for all 50 states and Washington, DC, giving many individual filers a potential single preparation workflow.
Pros: A fully offline Private Mode and a calculation layer without network calls give privacy-minded users a way to prepare without enabling AI.
Pros: PDF templates with field mapping and calculations traceable to tax authorities can make forms and calculation rationale easier to examine.
Cons: The published federal scope is for 2025, so it does not suit filers preparing another tax year.
Cons: The 85–90% coverage figure is an intended reach, not confirmation that a particular return or circumstance is supported.
Cons: AI functions require the user’s Anthropic API key, so they are not a turnkey option for people who do not already have one.

Alternatives

AI Tax Software is a broader category to browse if you want to compare AI tax tools rather than choose a single alternative.

For a different self-filing option, EZTax offers a monthly Self-Service ITR Filing plan at 249.00 INR per month, plus a free plan and free trial; choose it when that plan and its listed Android, iOS, web and Windows support fit your needs better.

H&R Block Online has a free online plan for simple situations using Form 1040, billed per state filed. It is the more directly described choice for a simple return that meets those limits; its Deluxe plan has no listed price.

Keeper offers a deductions-focused plan with expense discovery, tracking, a deduction summary export and a 24/7 AI Tax Assistant, as well as a Standard plan at 199.00 USD per year. Consider it when those deduction tools are a closer match than TelosTax’s 2025 form scope.

TaxAct offers free federal filing for eligible standard returns, with state filing additional, and lists web support. It may be a better fit for a standard return that meets its eligibility terms; its Deluxe plan is 59.99 USD.

Taxation.ai has a free plan for one federal return per year, five document uploads, a basic AI assistant and deduction finder, with API, self-hosted and web options. Choose it if those explicit free-plan limits and deployment options suit your workflow.

Taxfix offers a Basic individual annual plan at 39.99 EUR per year, with a self-prepared return free until submission. It is an alternative for someone who prefers that annual model and its Android, iOS and web platforms.

TaxGPT is another option to consider.

Instead is another option to consider.

Verdict

Choose TelosTax if you are an individual preparing a 2025 return and value a free, open-source tool with an offline mode, broad stated form coverage and traceable calculations. Its main reason to look elsewhere is decisive: the published federal scope is limited to 2025, and the project’s coverage target cannot confirm that your particular return is supported.

	Abacus	TelosTax
Free plan		Yes
Paid from		Free
Platforms	Web	Android, iOS, Linux, macOS, Web, Windows
Taxpayer types	business	personal
Document import	Yes	Yes
Filing support	none	both
Free plan		Yes
AI tax guidance		Yes
Deduction finding		Yes

Abacus vs TelosTax

Abacus

TelosTax