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2023 Checklist • 1120 - C Corporation Return

Tax Preparation Checklist to File Your Taxes

Reminder: 2023 taxes are due March 15, 2024 for calendar year filers


Tooltip icon Basic Info

Determine business return type for filing as registered with the IRS (Form 1065, 1120, or 1120S). If unsure, contact the IRS Business help line at 1-800-829-4933

Employer Identification Number (EIN) as registered with the IRS. If you don’t have an EIN, apply online at

List of states and state ID numbers in which your business has nexus or a presence that requires reporting

Copy of articles of incorporation or bylaws including any amendments

If entity has an accepted S election to be taxed as an S corporation, IRS acceptance letter or Form 2553, review current year filing requirements

Copy of Form 8832 if a check-the-box election was filed to be taxed as a corporation

Last year’s federal, state, and local tax returns

All amounts and dates for state and local estimated tax payments made

Information for each individual or entity owning 20% or more of corporation’s stock


file icon Documents Received

All Forms 1099-B, 1099-DIV, 1099-INT, 1099-K, or 1099-MISC received (or other records for dividends, interest, or business income)

Schedule K-1 received from entities that your business owns (lower tier entities)

All granted credit certificates issued by federal or state taxing authorities


folder icon Business and Financial Records

Trial balance report from company books. TaxAct’s Accounting Records import helps reduce time and errors by automatically transferring accounting records for the tax year via .csv import (compatible with most popular accounting applications)

Bank and credit card records to support interest and other day-to-day business expenses

Copy or summary of all Form 1099 and W-2 issued

Reports detailing all federal unemployment, Social Security, and Medicare tax paid (Forms 940 & 941)

Reports of state and local payroll tax paid

If business was conducted in multiple states, compile a report of sales, payroll, and property values for each state

Schedule of carryover losses, deductions, or credits from prior year tax returns

Reports for inventory including cost of goods or materials purchased for resale or manufacture and the total value of goods or materials at the end of year


folder icon Asset Records

Prior year depreciation schedules detailing asset cost, date placed in service, prior depreciation, and business use percentage

Date of purchase, cost, trade-in allowance, and business use percentage for all assets acquired during the tax year

Date of purchase, cost, sales proceeds, trade-in allowance, expenses of the sale, and accumulated depreciation for all assets disposed of during the tax year

Mileage log for each owned or leased vehicle (business use and total use)

Reports for business use percentage and actual expenses for each owned vehicle (gas and maintenance costs)

Pencil icon Notes