1. Form 1040 – U.S. Individual Income Tax Return

• This is the main form used by sole proprietors to file their personal income tax
  
• It includes all sources of income, including profits from the sole proprietorship
  
• The form consolidates income, deductions, and credits to determine final tax liability
  
• It must be filed annually by the due date, typically April 15
  
• Business income is included on this form along with personal income
  

2. Schedule C – Profit or Loss from Business

• Schedule C is used to report income and expenses from a sole proprietorship
  
• It is attached to Form 1040 as a supporting document
  
• Business expenses such as rent, supplies, and wages are listed to calculate net profit
  
• The net income from Schedule C flows into Form 1040
  
• This is a key form for measuring the financial performance of the business
  

3. Schedule SE – Self-Employment Tax

• This form calculates the self-employment tax owed by the sole proprietor
  
• It includes Social Security and Medicare contributions based on net earnings
  
• The results are reported on Form 1040 for total tax calculation
  
• Sole proprietors must pay this tax if net earnings exceed a specified threshold
  
• It helps determine eligibility for future Social Security and Medicare benefits
  

4. Form 1040-ES – Estimated Tax Payments

• Used to calculate and pay estimated taxes quarterly during the year
  
• Required if the sole proprietor expects to owe at least $1,000 in tax after credits
  
• Helps avoid penalties for underpayment of taxes throughout the year
  
• Includes estimated income, deductions, and tax owed for each quarter
  
• Payments are typically due in April, June, September, and January
  

5. Form W-9 and 1099-NEC (If Hiring Contractors)

• A sole proprietor may need to issue Form 1099-NEC to contractors they pay $600 or more
  
• Form W-9 is collected from the contractor to obtain their tax identification information
  
• These forms help the IRS track payments made to non-employees
  
• The 1099-NEC must be filed with the IRS and given to the contractor
  
• These are not used to report the owner’s income, but are part of reporting obligations