Schedule C education
A practical guide for freelancers, contractors, sole proprietors, and small business owners who need cleaner income, expense, receipt, and mileage records before filing.
Published by Cadus Labs LLC · Reviewed against the official IRS sources linked below.
Based on IRS Publication 334 (2025), IRS Schedule C instructions for 2025, and IRS Publication 463 guidance available in 2026.
The IRS uses Schedule C to report profit or loss from a business operated as a sole proprietorship. Many self-employed Cadus users keep records during the year so Schedule C work is not rebuilt from memory.
If a taxpayer operates more than one business, IRS Schedule C instructions say a separate Schedule C is completed for each business. That makes clear, business-by-business records especially important.
IRS Publication 334 explains that deductible business expenses generally need to be ordinary and necessary. Ordinary means common and accepted in the field, while necessary means helpful and appropriate for the business.
This is why a category label alone is not enough. A clean record should also preserve the receipt, amount, date, merchant, business purpose when needed, and whether any personal part was separated out.
Self-employed workers often need records for supplies, software, advertising, contract labor, professional fees, travel, vehicle costs, meals, business insurance, rent, utilities, phone, internet, and home business expenses.
Not every category applies to every business, and some costs need special rules, limits, or forms. Users should use IRS guidance or a tax professional before deciding what to claim.
Cadus helps users capture expenses, scan receipts, review bank transactions, track income, organize mileage, and generate reports so category review starts with better records.
The goal is not to replace tax software or professional advice. The goal is to make the underlying records cleaner before filing begins.
Estimated tax education
Learn how IRS quarterly estimated taxes work for self-employed workers, including Form 1040-ES, withholding, credits, and recordkeeping.
Mileage deduction education
Learn how business mileage records work, the 2026 IRS standard mileage rate, and how self-employed workers can keep cleaner trip and vehicle records.
IRS-backed tax education
Learn how the IRS home office deduction works for self-employed workers, including exclusive and regular use, simplified method, actual expenses, and Form 8829.
Cadus helps organize expense records and categories, but users are responsible for reviewing tax treatment with IRS guidance, tax software, or a qualified professional.
IRS Publication 334 describes an ordinary expense as common and accepted in the field, and a necessary expense as helpful and appropriate for the business.
Bank transactions show that money moved. Receipts and notes can help explain what was purchased and why it was connected to the business.