What Happened
Rob Balian, a developer, open-sourced a Claude Code skill that automates federal and state tax preparation. He tested it against TurboTax on his own 2024 and 2025 returns and got the same results - without clicking through 45 minutes of TurboTax's wizard interface.
The skill works in multiple stages: it reads source documents (W-2s, 1099s, brokerage statements, prior returns), asks clarifying questions, computes tax calculations including capital gains and carryover values, then downloads blank IRS PDFs and fills them programmatically. The output includes completed tax forms, federal and state summaries, carryover values for future years, and a checklist of items to review before filing.
Balian shared some honest learnings from the development process. The first iteration took almost an hour with lots of prompting, multiple context compactions, and PDF parsing issues. This reflects a real pattern with complex Claude Code skills - the initial setup is rough, but the reusable skill that comes out of it saves time on every subsequent run.
The project is on GitHub and accepting pull requests, timed for the current tax season.
Why It Matters
This is one of the more practical Claude Code skill implementations we've seen. Tax preparation is a perfect target for AI automation: it's document-heavy, rules-based, repetitive, and something almost everyone has to do. The fact that it matched TurboTax output on real returns (not synthetic test cases) is notable.
It also demonstrates something important about Claude Code's skill system. Skills aren't just text prompts - they can include scripts, code snippets, and example files. That makes them significantly more powerful than simple prompt templates. A skill that downloads PDFs, parses financial documents, runs calculations, and fills forms is closer to a traditional software application than a chatbot interaction.
For the roughly 50 million Americans who use commercial tax software and pay $50-200+ per return, a free open-source alternative is worth paying attention to - even if it requires some technical comfort with Claude Code.
Our Take
Let's be clear about what this is and what it isn't. This is a proof of concept that worked on one developer's returns. Tax situations vary wildly - business income, rental properties, foreign accounts, stock options - and the skill explicitly produces "mostly-complete" filings that require human review. Nobody should file taxes based solely on AI output without checking the numbers.
That said, the approach is sound. Tax preparation software has been overcharging for relatively straightforward work for years. TurboTax's business model depends on making a rules-based process feel complex enough to justify subscription pricing. An AI that can read your documents and apply the same rules without the upsell screens is a legitimate disruption path.
The more interesting signal here is what Claude Code skills are becoming. When the skill system launched, most skills were glorified system prompts. This tax filing skill includes document parsing, PDF manipulation, multi-step calculations, and form generation. That's a meaningful jump in capability. If this pattern catches on, we'll see Claude Code skills that replace entire categories of single-purpose software.
The timing is deliberate - tax season is here. If you're technically inclined and have a straightforward tax situation, this is worth trying as a second opinion alongside your normal filing method. Just don't skip the review step.