Startup Tax Forms: IRS Filing Guide for Startups

Most Common Startup Tax Forms

Corporate income tax & extensions

• Form 1120 – U.S. Corporation Federal Income Tax Return. The primary annual federal income tax return for C‑corporations, used to report your startup’s income, gains, losses, deductions, and credits and calculate tax liability.
  • Schedule G – Information on Certain Persons. Reports information on individuals and entities that own significant voting stock in your corporation, helping the IRS understand and monitor your startup’s ownership structure.
  • Schedule K – Other Information. Summarizes key details about your C‑corp, including ownership, accounting method, and certain transactions, to give the IRS more context about your startup’s activities.
  • Schedule L – Balance Sheets per Books. Reports your beginning‑ and end‑of‑year balance sheet, showing assets, liabilities, and equity as recorded in your accounting system.
  • Schedule M‑1 – Reconciliation of Income. Reconciles the difference between your startup’s book income (from financial statements) and taxable income on Form 1120, capturing timing and permanent differences.
  • Schedule M‑2 – Analysis of Unappropriated Retained Earnings. Tracks changes to retained earnings on your balance sheet, including distributions, prior‑period adjustments, and other equity‑related movements.
• Form 7004 – Application for Automatic Extension. Used to request an automatic six‑month extension to file your business income tax return.

Payroll, employees, and contractors

• Form 941 – Employer’s Quarterly Federal Tax Return. Filed every quarter by businesses with employees to report income and payroll taxes withheld, plus Social Security and Medicare payments.
• Form 940 – Employer’s Annual Federal Unemployment (FUTA) Tax Return. Annual FUTA filing; most employers also pay state unemployment tax.
• Form 944 – Employer’s Annual Federal Tax Return. Annual version of Form 941 for very small employers with $1,000 or less in annual liability.
• Form W‑2 – Wage and Tax Statement. Filed for every employee to report wages paid and taxes withheld.
• Form W‑3 – Transmittal of Wage and Tax Statements. Summary of all W‑2 wages and taxes, sent to the IRS and Social Security Administration.
• Form 1099 (NEC, DIV, INT, MISC) – Information Returns. Series of forms documenting payments to non‑employees such as contractors and other businesses; copies go to the payee and the IRS.
• Form 1125‑E – Compensation of Officers. Provides a detailed breakdown of officer compensation so you can substantiate salary and bonus deductions; required when your startup’s total receipts exceed $500,000 and filed with Form 1120.

Startup R&D and business tax credits

• Form 6765 – Credit for Increasing Research Activities. Documents qualified R&D expenses and calculates the federal Research & Development Tax Credit.
• Form 3800 – General Business Credit. Used to claim a variety of business credits, including carryforwards from prior years.
• Form 5884 – Work Opportunity Credit. Allows startups to claim credits for employing people from certain targeted groups (qualified veterans, summer youth employees, former felons, etc.).
• Form 8844 – Empowerment Zone and Renewal Community Employment Credit. Allows eligible employers to claim a credit for wages paid to certain employees who live and work in designated empowerment zones or renewal communities, potentially lowering your tax bill if your operations qualify.
• Form 8941 – Credit for Small Employer Health Insurance Premiums. Allows very small employers (under 25 employees, average salary below $50,000) claim a credit for health insurance premiums, though few high‑salary startups qualify.
• Form 8994 – Employer Credit for Paid Family and Medical Leave. Computes the credit for qualifying paid family and medical leave benefits provided to employees.

Entity setup, fiscal year, and accounting method

• Form SS‑4 – Application for Employer Identification Number (EIN). Used by new businesses to obtain their nine‑digit EIN for tax filing and reporting.
• Form 8832 – Entity Classification Election. Lets companies elect their federal tax classification (for example, corporation vs. partnership).
• Form 1128 – Application To Adopt, Change, or Retain a Tax Year. Used to change your company’s tax year, for example when shifting to a non‑calendar fiscal year.
• Form 3115 – Application for Change in Accounting Method. Required to change from cash to accrual accounting, which Kruze generally recommends for funded startups.

Equity, capital assets, and IP

• Form 3921 – Exercise of an Incentive Stock Option. Reports incentive stock option exercises for employees; one form is required for each ISO exercise.
• Form 4562 – Depreciation & Amortization Deductions. Claims deductions for depreciation and amortization, elects to expense certain property, and reports business use of property and vehicles.
• Form 4797 – Sales of Business Property. Reports the sale or exchange of business property or capital assets.
• Form 8949 – Sales & Other Dispositions of Capital Assets. Reconciles amounts on Forms 1099‑B and 1099‑S with the startup’s tax return.
• Form 8992 – U.S. Shareholder Global Intangible Low‑Taxed Income (GILTI). Used by startups developing significant IP in foreign jurisdictions to report certain overseas income from US‑controlled corporations.

Health insurance and benefits

• Form 1095‑B – Health Coverage. Reports individuals covered under a company’s health insurance to the IRS.
• Form 1095‑C – Employer‑Provided Health Insurance Offer and Coverage. Reports full‑time employees of Applicable Large Employers (ALE) and the health coverage offered.
• Form 8941 – Credit for Small Employer Health Insurance Premiums. Used by businesses with fewer than 25 employees and an average annual salary of less than $50,000 to apply for a tax credit on health insurance premiums. Very limited applicability to typical VC‑backed startups due to salary thresholds.

International and foreign shareholders

• Form 5471 – Information Return of U.S. Persons with Respect to Certain Foreign Corporations. Required for US citizens and residents with certain ownership in foreign corporations.
• Form 5472 – Information Return of a 25% Foreign‑Owned US Corporation or a Foreign Corporation Engaged in a US Trade or Business. Filed by foreign individuals or corporations that own more than 25% of a startup or conduct US trade or business.
• Form W‑8 series – Certificate of Foreign Status of Beneficial Owner for United States Tax Withholding and Reporting (Individuals). Group of forms documenting income for any non‑resident aliens your startup pays or employs; very complex and highly fact‑specific.

Home office and other specialized forms

• Form 720 – Quarterly Federal Excise Tax Return. Filed quarterly if your startup owes federal excise taxes on certain goods, services, or activities.
• Form 8829 – Expenses for Business Use of Your Home. Documents home office expenses; the IRS scrutinizes this form closely due to frequent abuse.

Accurate startup accounting depends on knowing which IRS forms apply to your Delaware C‑corp and how they fit into your overall compliance calendar.

This table brings together the key startup tax forms in one place so founders and finance teams can quickly see what each form does, when it's used, and how it supports clean, investor‑ready books.