United States Tax Knowledge Base

Browse practical answers to common tax questions for United States self-employed individuals, sole traders, and freelancers. Select a category or search for your question.

Getting Started

  • How does tax work for self-employed Americans?
  • When does the US tax year start and end?
  • Who needs to file a Schedule C?
  • Do I need an EIN (Employer Identification Number) as a self-employed person?
  • What is the difference between receiving a 1099-NEC and a W-2?

Se Tax

  • What is Self-Employment Tax and how is it calculated?
  • Can I deduct half my Self-Employment Tax?
  • What is Schedule SE and when do I need to file it?

Income Tax

  • What are the federal income tax rates for 2025?
  • What is the Standard Deduction for self-employed individuals in 2025?
  • What is Adjusted Gross Income (AGI) and why does it matter?
  • What is the SALT deduction cap and does it affect self-employed individuals?
  • How do ACA marketplace plans and subsidies work for self-employed individuals?

Schedule C

  • How do I complete Schedule C as a self-employed person?
  • What is the difference between gross income and net profit on Schedule C?
  • How do I handle 1099-NEC forms I receive as a freelancer?

Quarterly Taxes

  • How do quarterly estimated taxes work for the self-employed?
  • What is the Safe Harbor Rule for quarterly estimated taxes?
  • What is the penalty for underpaying quarterly estimated taxes?

Deductions

  • What counts as a deductible business expense on Schedule C?
  • How does the home office deduction work on Schedule C?
  • How do I deduct car and vehicle expenses on Schedule C?
  • Can self-employed individuals deduct health insurance premiums?
  • What is the Section 179 deduction and how does it work for equipment?

Qbi Sstb

  • What is the Qualified Business Income (QBI) deduction?
  • What is a Specified Service Trade or Business (SSTB) and how does it affect the QBI deduction?
  • How do I claim the QBI deduction on my tax return (Form 8995)?

Retirement

  • How does a SEP-IRA work for self-employed individuals?
  • What is a Solo 401(k) and how does it differ from a SEP-IRA?
  • What is a SIMPLE IRA and can self-employed individuals use it?

State Taxes

  • Which states have no income tax for self-employed individuals?

Record Keeping

  • How long must I keep tax records as a self-employed person?
  • What bookkeeping system should a self-employed person use?
  • What are the IRS requirements for a mileage log?
  • What triggers an IRS audit for self-employed individuals?

Nexus

  • What is state tax nexus and does it apply to me as a freelancer?
  • When do self-employed individuals need to collect sales tax?
  • What is New York's 'convenience of the employer' rule?
  • What happens to my taxes if I move to a new state mid-year?
  • How do states source self-employment income when I work for clients in multiple states?

Related Resources

  • Frequently Asked Questions
  • Tax Glossary
  • Profession Guides