Different business structures (sole proprietorship, partnership, corporation, or limited liability company) have different income tax requirements regarding filing dates, forms required, and tax rates and calculations.
The IRS lists the various business taxes and forms required for each legal structure:
Federal income tax is a pay-as-you-go tax. Most business owners will need to pay income taxes in quarterly estimated income tax payments. For more information on estimated income tax payments, refer to IRS Publication 505, Tax Withholding and Estimated Tax. We also recommend that you read through IRS Publication 583, Starting a Business and Keeping Records, which provides basic federal tax information for people who are starting a business.