Individuals file their annual income tax returns to report earnings from employment, investments, and other sources. Deductions and credits are applied to determine tax liability or refund eligibility.

Businesses file tax returns to report profits earned from operations. This includes income from sales, services, and investments, while deductions such as expenses and depreciation are used to calculate taxable income.

Self-employed individuals report income earned from freelance work, contracting, or owning a business. They must account for business expenses, deductions, and self-employment taxes, ensuring compliance with tax laws.

Individuals or businesses earning rental income from properties file tax returns. They report rental earnings, deduct allowable expenses like maintenance and mortgage interest, and comply with specific tax regulations governing rental income.

Investors file tax returns on income earned from investments such as dividends, interest, and capital gains. They report earnings, apply deductions for investment expenses, and calculate taxes owed based on holding periods and tax rates.

Individuals or businesses with international income sources file tax returns, complying with both domestic and foreign tax laws. This involves reporting foreign earnings, applying tax treaties, and addressing complexities like foreign tax credits and reporting requirements.