General Instructions

Purpose of Form

Use Form 1120, U.S. Corporation Income Tax Return, to report the income, gains, losses, deductions, credits, and to figure the income tax liability of a corporation.

Who Must File

Unless exempt under section 501, all domestic corporations (including corporations in bankruptcy) must file an income tax return whether or not they have taxable income. Domestic corporations must file Form 1120, unless they are required, or elect to file a special return. See Special Returns for Certain Organizations, below.

Entities electing to be taxed as corporations.    A domestic entity electing to be classified as an association taxable as a corporation must file Form 1120, unless it is required to, or elects to file a special return listed under Special Returns for Certain Organizations, below. The entity must also file Form 8832, Entity Classification Election, and attach a copy of Form 8832 to Form 1120 (or the applicable return) for the year of the election. For more information, see Form 8832 and its instructions.

Limited liability companies.   If an entity with more than one owner was formed as an LLC under state law, it generally is treated as a partnership for federal income tax purposes and files Form 1065, U.S. Return of Partnership Income. Generally, a single-member LLC is disregarded as an entity separate from its owner and reports its income and deductions on its owner's federal income tax return. The LLC can file a Form 1120 only if it has filed Form 8832 to elect to be treated as an association taxable as a corporation. For more information about LLCs, see Pub. 3402, Taxation of Limited Liability Companies.

Corporations engaged in farming.   A corporation (other than a corporation that is a subchapter T cooperative) that engages in farming should use Form 1120 to report the income (loss) from such activities. Enter the income and deductions of the corporation according to the instructions for lines 1 through 10 and 12 through 29.

Ownership interest in a Financial Asset Securitization Investment Trust (FASIT).   Special rules apply to a FASIT in existence on October 22, 2004, to the extent that regular interests issued by the FASIT before October 22, 2004, continue to remain outstanding in accordance with their original terms.

  If a corporation holds an ownership interest in a FASIT to which these special rules apply, it must report all items of income, gain, deductions, losses, and credits on the corporation's income tax return (except as provided in section 860H). Show a breakdown of the items on an attached statement. For more information, see sections 860H and 860L (repealed with certain exceptions).

Electronic Filing

Corporations can generally electronically file (e-file) Form 1120, related forms, schedules, and attachments, Form 7004 (automatic extension of time to file) and Forms 940, 941 and 944 (employment tax returns). If there is a balance due, the corporation can authorize an electronic funds withdrawal while e-filing. Form 1099 and other information returns can also be electronically filed.

Exceptions.   The option to e-file generally does not apply to certain returns, including:
  • Returns with precomputed penalty and interest,

  • Returns with reasonable cause for failing to file timely,

  • Returns with reasonable cause for failing to pay timely, and

  • Returns with requests for overpayments to be applied to another account.

Required e-filers.   Certain corporations with total assets of $10 million or more that file at least 250 returns a year are required to e-file Form 1120, even if any of the above exceptions apply. See Regulations section 301.6011-5. However, these corporations can request a waiver of the electronic filing requirements. See Notice 2010-13, 2010-4 I.R.B. 327.

  Visit for more information.

Special Returns for Certain Organizations

Instead of filing Form 1120, certain organizations, as shown below, file special returns.

If the organization is a: File Form
Exempt organization with unrelated trade or business income 990-T
Religious or apostolic organization exempt under section 501(d) 1065
Entity formed as a limited liability company under state law and treated as a partnership for federal income tax purposes 1065
Subchapter T cooperative association (including a farmers' cooperative) 1120-C
Entity that elects to be treated as a real estate mortgage investment conduit (REMIC) under section 860D 1066
Interest charge domestic international sales corporation (section 992) 1120-IC-DISC
Foreign corporation (other than life and property and casualty insurance company filing Form 1120-L or Form 1120-PC) 1120-F
Foreign sales corporation (section 922) 1120-FSC
Condominium management, residential real estate management, or timeshare association that elects to be treated as a homeowners association under section 528 1120-H
Life insurance company  
(section 801)
Fund set up to pay for nuclear decommissioning costs (section 468A) 1120-ND
Property and casualty insurance company  
(section 831)
Political organization  
(section 527)
Real estate investment trust (section 856) 1120-REIT
Regulated investment company (section 851) 1120-RIC
S corporation (section 1361) 1120S
Settlement fund  
(section 468B)

Where To File

File the corporation's return at the applicable IRS address listed below.

If the corporation's principal business, office, or agency is located in: And the total assets at the end of the tax year are: Use the following address:
Connecticut, Delaware, District of Columbia, Georgia, Illinois, Indiana, Kentucky, Maine, Maryland, Massachusetts, Michigan, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Vermont, Virginia, West Virginia, Wisconsin Less than $10 million and Schedule M-3 is not filed Department of the Treasury 
Internal Revenue Service Center 
Cincinnati, OH 45999-0012
$10 million or more or 
less than $10 million and 
Schedule M-3 is filed
Department of the Treasury 
Internal Revenue Service Center 
Ogden, UT 84201-0012
Alabama, Alaska, Arizona, Arkansas, California, Colorado, Florida, Hawaii, Idaho, Iowa, Kansas, Louisiana, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Mexico, North Dakota, Oklahoma, Oregon, South Dakota, Texas, Utah, Washington, Wyoming Any amount Department of the Treasury 
Internal Revenue Service Center 
Ogden, UT 84201-0012
A foreign country or U.S. possession
Any amount Internal Revenue Service Center 
P.O. Box 409101 
Ogden, UT 84409

A group of corporations with members located in more than one service center area will often keep all the books and records at the principal office of the managing corporation. In this case, the tax returns of the corporations may be filed with the service center for the area in which the principal office of the managing corporation is located.

When To File

Generally, a corporation must file its income tax return by the 15th day of the 3rd month after the end of its tax year. A new corporation filing a short-period return must generally file by the 15th day of the 3rd month after the short period ends. A corporation that has dissolved must generally file by the 15th day of the 3rd month after the date it dissolved.

If the due date falls on a Saturday, Sunday, or legal holiday, the corporation can file on the next business day.

Private Delivery Services

Corporations can use certain private delivery services designated by the IRS to meet the “timely mailing as timely filing” rule for tax returns. These private delivery services include only the following.

  • DHL Express (DHL): DHL Same Day Service.

  • Federal Express (FedEx): FedEx Priority Overnight, FedEx Standard Overnight, FedEx 2Day, FedEx International Priority, and FedEx International First.

  • United Parcel Service (UPS): UPS Next Day Air, UPS Next Day Air Saver, UPS 2nd Day Air, UPS 2nd Day Air A.M., UPS Worldwide Express Plus, and UPS Worldwide Express.

The private delivery service can tell you how to get written proof of the mailing date.

Private delivery services cannot deliver items to P.O. boxes. You must use the U.S. Postal Service to mail any item to an IRS P.O. box address.

Extension of Time To File

File Form 7004, Application for Automatic Extension of Time To File Certain Business Income Tax, Information, and Other Returns, to request a 6-month extension of time to file. Generally, the corporation must file Form 7004 by the regular due date of the return. See the Instructions for Form 7004.

Who Must Sign

The return must be signed and dated by:

  • The president, vice president, treasurer, assistant treasurer, chief accounting officer; or

  • Any other corporate officer (such as tax officer) authorized to sign.

If a return is filed on behalf of a corporation by a receiver, trustee, or assignee, the fiduciary must sign the return, instead of the corporate officer. Returns and forms signed by a receiver or trustee in bankruptcy on behalf of a corporation must be accompanied by a copy of the order or instructions of the court authorizing signing of the return or form.

If an employee of the corporation completes Form 1120, the paid preparer space should remain blank. Anyone who prepares Form 1120 but does not charge the corporation should not complete that section. Generally, anyone who is paid to prepare the return must sign it and fill in the “Paid Preparer Use Only” area.

The paid preparer must complete the required preparer information and:

  • Sign the return in the space provided for the preparer's signature.

  • Give a copy of the return to the taxpayer.


A paid preparer may sign original or amended returns by rubber stamp, mechanical device, or computer software program.

Paid Preparer Authorization

If the corporation wants to allow the IRS to discuss its 2011 tax return with the paid preparer who signed it, check the “Yes” box in the signature area of the return. This authorization applies only to the individual whose signature appears in the “Paid Preparer Use Only” section of the return. It does not apply to the firm, if any, shown in that section.

If the “Yes” box is checked, the corporation is authorizing the IRS to call the paid preparer to answer any questions that may arise during the processing of its return. The corporation is also authorizing the paid preparer to:

  • Give the IRS any information that is missing from the return,

  • Call the IRS for information about the processing of the return or the status of any related refund or payment(s), and

  • Respond to certain IRS notices about math errors, offsets, and return preparation.

The corporation is not authorizing the paid preparer to receive any refund check, bind the corporation to anything (including any additional tax liability), or otherwise represent the corporation before the IRS.

The authorization will automatically end no later than the due date (excluding extensions) for filing the corporation's 2012 tax return. If the corporation wants to expand the paid preparer's authorization or revoke the authorization before it ends, see Pub. 947, Practice Before the IRS and Power of Attorney.

Assembling the Return

To ensure that the corporation's tax return is correctly processed, attach all schedules and other forms after page 5 of Form 1120 in the following order.

  1. Schedule N (Form 1120).

  2. Schedule O (Form 1120).

  3. Form 4626.

  4. Form 8050.

  5. Form 1125-A.

  6. Form 4136.

  7. Form 8941.

  8. Form 5884-B.

  9. Form 3800.

  10. Additional schedules in alphabetical order.

  11. Additional forms in numerical order.

  12. Supporting statements and attachments.

Complete every applicable entry space on Form 1120. Do not enter “See Attached” or “Available Upon Request” instead of completing the entry spaces. If more space is needed on the forms or schedules, attach separate sheets using the same size and format as the printed forms.

If there are supporting statements and attachments, arrange them in the same order as the schedules or forms they support and attach them last. Show the totals on the printed forms. Enter the corporation's name and EIN on each supporting statement or attachment.

Tax Payments

The corporation must pay any tax due in full no later than the 15th day of the 3rd month after the end of the tax year.

Electronic Deposit Requirement

Corporations must use electronic funds transfers to make all federal tax deposits (such as deposits of employment, excise, and corporate income tax). Generally, electronic funds transfers are made using the Electronic Federal Tax Payment System (EFTPS). However, if the corporation does not want to use EFTPS, it can arrange for its tax professional, financial institution, payroll service, or other trusted third party to make deposits on its behalf. Also, it may arrange for its financial institution to initiate a same-day tax wire payment (discussed below) on its behalf. EFTPS is a free service provided by the Department of the Treasury. Services provided by a tax professional, financial institution, payroll service, or other third party may have a fee.

To get more information about EFTPS or to enroll in EFTPS, visit, or call 1-800-555-4477. Additional information about EFTPS is also available in Pub. 966, The Secure Way to Pay Your Federal Taxes.


Forms 8109 and 8109-B, Federal Tax Deposit Coupon, can no longer be used to make federal tax deposits.

Depositing on time.    For deposits made by EFTPS to be on time, the corporation must initiate the deposit by 8 p.m. Eastern time the day before the date the deposit is due. If the corporation uses a third party to make deposits on its behalf, they may have different cutoff times.

Same-day wire payment option.    If the corporation fails to initiate a deposit transaction on EFTPS by 8 p.m. Eastern time the day before the date a deposit is due, it can still make the deposit on time by using the Federal Tax Application (FTA). Before using the same-day wire payment option, the corporation will need to make arrangements with its financial institution ahead of time. Please check with the financial institution regarding availability, deadlines, and costs. To learn more about making a same-day wire payment and download the Same-Day Payment Worksheet, visit

Estimated Tax Payments

Generally, the following rules apply to the corporation's payments of estimated tax.

  • The corporation must make installment payments of estimated tax if it expects its total tax for the year (less applicable credits) to be $500 or more.

  • The installments are due by the 15th day of the 4th, 6th, 9th, and 12th months of the tax year. If any date falls on a Saturday, Sunday, or legal holiday, the installment is due on the next regular business day.

  • The corporation must use electronic funds transfers to make installment payments of estimated tax. See the Instructions for Form 1120-W.

  • Use Form 1120-W, Estimated Tax for Corporations, as a worksheet to compute estimated tax.

  • If the corporation overpaid estimated tax, it may be able to get a quick refund by filing Form 4466, Corporation Application for Quick Refund of Overpayment of Estimated Tax. See the instructions for Schedule J, Part II, line 14.

Estimated tax penalty.   A corporation that does not make estimated tax payments when due may be subject to an underpayment penalty for the period of underpayment. Generally, a corporation is subject to the penalty if its tax liability is $500 or more and it did not timely pay at least the smaller of:
  • Its tax liability for the current year, or

  • Its prior year's tax.

  Use Form 2220, Underpayment of Estimated Tax by Corporations, to see if the corporation owes a penalty and to figure the amount of the penalty. If Form 2220 is completed, enter the penalty on line 33. See the instructions for line 33.

Interest and Penalties

If the corporation receives a notice about interest and penalties after it files its return, send the IRS an explanation and we will determine if the corporation meets reasonable-cause criteria. Do not attach an explanation when the corporation's return is filed.

Interest.   Interest is charged on taxes paid late even if an extension of time to file is granted. Interest is also charged on penalties imposed for failure to file, negligence, fraud, substantial valuation misstatements, substantial understatements of tax, and reportable transaction understatements from the due date (including extensions) to the date of payment. The interest charge is figured at a rate determined under section 6621.

Late filing of return.   A corporation that does not file its tax return by the due date, including extensions, may be penalized 5% of the unpaid tax for each month or part of a month the return is late, up to a maximum of 25% of the unpaid tax. The minimum penalty for a return that is over 60 days late is the smaller of the tax due or $135. The penalty will not be imposed if the corporation can show that the failure to file on time was due to reasonable cause. See Caution, above.

Late payment of tax.   A corporation that does not pay the tax when due generally may be penalized ½ of 1% of the unpaid tax for each month or part of a month the tax is not paid, up to a maximum of 25% of the unpaid tax. See Caution, above.

Trust fund recovery penalty.   This penalty may apply if certain excise, income, social security, and Medicare taxes that must be collected or withheld are not collected or withheld, or these taxes are not paid. These taxes are generally reported on:
  • Form 720, Quarterly Federal Excise Tax Return;

  • Form 941, Employer's QUARTERLY Federal Tax Return;

  • Form 943, Employer's Annual Federal Tax Return for Agricultural Employees;

  • Form 944, Employer's ANNUAL Federal Tax Return; or

  • Form 945, Annual Return of Withheld Federal Income Tax.

  The trust fund recovery penalty may be imposed on all persons who are determined by the IRS to have been responsible for collecting, accounting for, and paying over these taxes, and who acted willfully in not doing so. The penalty is equal to the full amount of the unpaid trust fund tax. See the Instructions for Form 720, Pub. 15 (Circular E), Employer's Tax Guide, or Pub. 51 (Circular A), Agricultural Employer's Tax Guide, for details, including the definition of responsible persons.

Other penalties.   Other penalties can be imposed for negligence, substantial understatement of tax, reportable transaction understatements, and fraud. See sections 6662, 6662A, and 6663.

Accounting Methods

Figure taxable income using the method of accounting regularly used in keeping the corporation's books and records. In all cases, the method used must clearly show taxable income. Permissible methods include cash, accrual, or any other method authorized by the Internal Revenue Code.

Generally, the following rules apply.

  • A corporation (other than a qualified personal service corporation) must use the accrual method of accounting if its average annual gross receipts exceed $5 million. However, see Nonaccrual experience method for service providers, in the instructions for line 1b.

  • Unless it is a qualifying taxpayer or a qualifying small business taxpayer, a corporation must use the accrual method for sales and purchases of inventory items. See the instructions for Form 1125-A.

  • A corporation engaged in farming must use the accrual method. For exceptions, see section 447.

  • Special rules apply to long-term contracts. See section 460.

  • Dealers in securities must use the mark-to-market accounting method. Dealers in commodities and traders in securities and commodities can elect to use the mark-to-market accounting method. See section 475.

Change in accounting method.   Generally, the corporation must get IRS consent to change the method of accounting used to report taxable income (for income as a whole or for the treatment of any material item). To do so, the corporation generally must file Form 3115, Application for Change in Accounting Method. For more information, see the Instructions for Form 3115, and Pub. 538, Accounting Periods and Methods.

  There are some instances when the corporation can obtain automatic consent from the IRS to change to certain accounting methods. See Rev. Proc. 2011-14, 2011-4 I.R.B. 330, as modified, or its successor.

Accounting Period

A corporation must figure its taxable income on the basis of a tax year. A tax year is the annual accounting period a corporation uses to keep its records and report its income and expenses. Generally, corporations can use a calendar year or a fiscal year. Personal service corporations, however, must use a calendar year unless they meet one of the exceptions, discussed later under Personal Service Corporation.

Change of tax year.   Generally, a corporation, including a personal service corporation, must get the consent of the IRS before changing its tax year by filing Form 1128, Application To Adopt, Change, or Retain a Tax Year. However, under certain conditions, a corporation can change its tax year without getting consent.

  See the Instructions for Form 1128 and Pub. 538 for more information on accounting periods and tax years.

Rounding Off to Whole Dollars

The corporation can round off cents to whole dollars on its return and schedules. If the corporation does round to whole dollars, it must round all amounts. To round, drop amounts under 50 cents and increase amounts from 50 to 99 cents to the next dollar. For example, $1.39 becomes $1 and $2.50 becomes $3.

If two or more amounts must be added to figure the amount to enter on a line, include cents when adding the amounts and round off only the total.


Keep the corporation's records for as long as they may be needed for the administration of any provision of the Internal Revenue Code. Usually, records that support an item of income, deduction, or credit on the return must be kept for 3 years from the date the return is due or filed, whichever is later. Keep records that verify the corporation's basis in property for as long as they are needed to figure the basis of the original or replacement property.

The corporation should keep copies of all filed returns. They help in preparing future and amended returns and in the calculation of earnings and profits.

Other Forms and Statements That May Be Required

Amended return.   Use Form 1120X, Amended U.S. Corporation Income Tax Return, to correct a previously filed Form 1120.

Reportable transaction disclosure statement.   Disclose information for each reportable transaction in which the corporation participated. Form 8886, Reportable Transaction Disclosure Statement, must be filed for each tax year that the federal income tax liability of the corporation is affected by its participation in the transaction. The following are reportable transactions.
  1. Any listed transaction, which is a transaction that is the same as or substantially similar to one of the types of transactions that the IRS has determined to be a tax avoidance transaction and identified by notice, regulation, or other published guidance as a listed transaction.

  2. Any transaction offered under conditions of confidentiality for which the corporation (or a related party) paid an advisor a fee of at least $250,000.

  3. Certain transactions for which the corporation (or a related party) has contractual protection against disallowance of the tax benefits.

  4. Certain transactions resulting in a loss of at least $10 million in any single year or $20 million in any combination of years.

  5. Any transaction identified by the IRS by notice, regulation, or other published guidance as a “transaction of interest.

  For more information, see Regulations section 1.6011-4. Also see the Instructions for Form 8886.


The corporation may have to pay a penalty if it is required to disclose a reportable transaction under section 6011 and fails to properly complete and file Form 8886. Penalties may also apply under section 6707A if the corporation fails to file Form 8886 with its corporate return, fails to provide a copy of Form 8886 to the Office of Tax Shelter Analysis (OTSA), or files a form that fails to include all the information required (or includes incorrect information). Other penalties, such as an accuracy-related penalty under section 6662A, may also apply. See the Instructions for Form 8886 for details on these and other penalties.

Reportable transactions by material advisors.   Material advisors to any reportable transaction must disclose certain information about the reportable transaction by filing Form 8918, Material Advisor Disclosure Statement, with the IRS. For details, see the Instructions for Form 8918.

Transfers to a corporation controlled by the transferor.   Every significant transferor (as defined in Regulations section 1.351-3(d)) that receives stock of a corporation in exchange for property in a nonrecognition event must include the statement required by Regulations section 1.351-3(a) on or with the transferor's tax return for the tax year of the exchange. The transferee corporation must include the statement required by Regulations section 1.351-3(b) on or with its return for the tax year of the exchange, unless all the required information is included in any statement(s) provided by a significant transferor that is attached to the same return for the same section 351 exchange. If the transferor or transferee corporation is a controlled foreign corporation, each U.S. shareholder (within the meaning of section 951(b)) must include the required statement on or with its return.

Distributions under section 355.   Every corporation that makes a distribution of stock or securities of a controlled corporation, as described in section 355 (or so much of section 356 as it relates to section 355), must include the statement required by Regulations section 1.355-5 on or with its return for the year of the distribution. If the distributing corporation is a controlled foreign corporation, each U.S. shareholder (within the meaning of section 951(b)), must include the statement on or with its return.

Dual consolidated losses.   If a domestic corporation incurs a dual consolidated loss (as defined in Regulations section 1.1503-2(c)(5)), the corporation (or consolidated group) may need to attach an elective relief agreement and/or an annual certification as provided in Regulations section 1.1503-2(g)(2).

Election to reduce basis under section 362(e)(2)(C).   The transferor may make an election under section 362(e)(2)(C) to limit the transferor's basis in the stock received instead of the transferor's basis in the transferred property. The transferor can make the election by including the certification provided in Notice 2005-70, 2005-41 I.R.B. 694 on or with its tax return filed by the due date (including extensions) for the tax year in which the transaction occurred. If the transferor is a controlled foreign corporation, its controlling U.S. shareholder(s) can make the election. The common parent of a consolidated group can make the election for the group.

  If the election is made as described above, no election need be made by the transferee (or any controlling U.S. shareholder thereof).

  Once made, the election is irrevocable. See section 362(e)(2)(C) and Notice 2005-70.

Annual information statement for elections under section 108(i).   If the corporation made an election in 2009 or 2010 to defer income from cancellation of debt (COD) in connection with the reacquisition of an applicable debt instrument, the corporation must attach a statement to its return beginning with the tax year following the tax year for which the corporation made the election, and ending the first tax year all income deferred has been included in income. The statement must be labeled “Section 108(i) Information Statement” and must clearly identify, for each applicable debt instrument to which an election under section 108(i) applies, the following.
  1. Any deferred COD income that is included in income in the current tax year.

  2. Any deferred COD income that has been accelerated because of an event described in section 108(i)(5)(D) and must be included in income in the current tax year. Include a description and the date of the acceleration event.

  3. Any deferred COD income that has not been included in income in the current or prior tax years.

  4. Any deferred OID deduction allowed as a deduction in the current tax year.

  5. Any deferred OID deduction that is allowed as a deduction in the current tax year because of an accelerated event described in section 108(i)(5)(D).

  6. Any deferred OID deduction that has not been deducted in the current or prior tax years.

  In addition, include a copy of the election statement the corporation filed to make the election to defer the income. For more information on deferring the income, see the instructions for line 10. For more information regarding the annual information statement, see Rev. Proc. 2009-37, 2009-36 I.R.B. 309.

Other forms and statements.   See Pub. 542, Corporations, for a list of other forms and statements a corporation may need to file in addition to the forms and statements discussed throughout these instructions.

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