Schedule C Tax Prep Workbook

A Claude Skill that does the THINKING part of self-employment taxes: it turns a pile of 1099s and a messy expense export into a complete, defensible IRS Schedule C (Form 1040) worksheet — every line filled, every deduction flagged, every audit risk noted — ready to punch into TurboTax/FreeTaxUSA or hand to a CPA.

Built for the 2025 tax year (the return filed by April 15, 2026).

NOT TAX ADVICE. This Skill produces a worksheet for your review or your CPA's review. Final positions on your tax return are your responsibility.

WHO IT'S FOR

Solo sole proprietors, 1099 contractors, freelancers, and single-member LLCs taxed as sole props, with gross receipts roughly $20K–$250K, who are either doing their own taxes or prepping a clean handoff to a CPA.

WHAT IT DOES

1. Line-by-line Schedule C worksheet — Part I income, Part II expenses (lines 8–27), Part III COGS, Part IV vehicle, Part V other — every line slotted with your numbers.
2. Expense categorization engine — drop in a CSV/bank export/paste; it maps each row to the correct Schedule C line, flags ambiguous rows for review, never silently miscategorizes.
3. Deduction flagging — home office (simplified vs. actual), vehicle (standard mileage vs. actual), QBI/§199A, self-employed health insurance, SEP-IRA/Solo 401(k) room, startup costs, §179 vs. bonus depreciation.
4. Audit-risk memo — flags high-audit-risk patterns with the IRC cite and the exact records to substantiate each.
5. Quarterly estimated tax — 1040-ES Q1–Q4 amounts plus safe-harbor analysis.
6. Handoff package — a TurboTax/FreeTaxUSA interview crosswalk, or a one-page CPA summary memo.

THREE WORKED EXAMPLES INCLUDED — Freelance designer ($85K, home office + vehicle), Consultant LLC ($180K with SEP-IRA + SE health + QBI), Etsy seller ($42K COGS-heavy). Each produces a complete line-by-line Schedule C, not a summary.

WHY $25? TurboTax Self-Employed is $129+ every year. This is $25 once and re-usable next year as IRS limits update. The QBI taxable-income math in here is the exact place TurboTax buries people.