Form 1120X Tax Year 2013 Filing Checklist
Year-Specific Context
Form 1120X for tax year 2013 operates under pre-Tax Cuts and Jobs Act provisions, as the TCJA was not enacted until December 2017. The 2013 tax year employs graduated corporate tax rates of 15 percent, 25 percent, 34 percent, and 35 percent, with an additional tax applied to certain income levels. This structure remained consistent with prior years and was not modified for 2013.
For 2013, the period for carrying back net operating losses is generally two years, with a carryforward allowed for up to 20 years. Certain types of losses have different carryback periods. The five-year carryback provision for eligible small business credits under Section 38(c)(5), enacted by the Small Business Jobs Act of 2010, remains applicable to qualifying corporations in 2013.
Net Operating Loss and Credit Carryback Rules
Net operating losses incurred in 2013 may generally be carried back two years to 2011 and 2010, and carried forward 20 years to tax years 2014 through 2033. Farming losses have special rules that allow for more extended carryback periods. The corporation may elect to forego the carryback period and carry the NOL forward by selecting the return for the year in which the NOL was incurred.
Eligible small business credits may be carried back five years under Section 38(c)(5). This provision applies to corporations meeting the small business definition with average annual gross receipts not exceeding 50 million dollars for the three years preceding the credit year. The five-year carryback applies to the general business credit portion attributable to eligible small business credits.
Ten-Step Filing Checklist
Step 1: Gather Original Return and Supporting Documentation
Obtain the complete original Form 1120 as filed for the 2013 tax year, including all schedules and supporting forms. Collect all Forms W-2 for officer and employee compensation, Forms 1099 for non-employee compensation and other payments, and any Schedule K-1 forms received from pass-through entities. Gather documentation supporting all income, deductions, credits, and other items reported on the original return.
This checklist is for educational purposes only and does not constitute tax or legal advice. Always review official IRS instructions and consult a qualified professional for guidance.
Step 2: Verify Income and Deduction Amounts
Review the total income reported on line 1 of the original Form 1120, including gross receipts, dividends, interest, capital gains, and other income sources. Verify total deductions reported on line 2, including officer compensation, salaries and wages, repairs, bad debts, rents, taxes, interest, charitable contributions, depreciation, and other ordinary and necessary business expenses.
Identify all items requiring correction or amendment. Prepare supporting documentation for each change, including revised calculations, corrected Forms 1099, amended depreciation schedules, or other substantiation.
Step 3: Review Schedule J Tax Computation
If taxable income or tax calculations require adjustment, review Schedule J from the original 2013 Form 1120. Apply the graduated corporate tax rates applicable to 2013: 15 percent on taxable income up to 50,000 dollars, 25 percent on income from 50,001 to 75,000 dollars, 34 percent on income from 75,001 to 10 million dollars, and 35 percent on income exceeding 10 million dollars.
Additional tax applies to corporations with taxable income between $100,000 and $335,000, and to corporations with taxable income between $15 million and $18,333,333. Recalculate tax liability using the corrected taxable income amount to determine the revised tax due or overpayment.
Step 4: Complete Form 1120X Three-Column Format
Enter amounts as originally reported or as previously adjusted in column (a). Show net changes in column (b), using positive numbers for increases and parentheses for decreases. Enter the corrected amounts in the column (c). Column (c) must equal column (a) plus or minus column (b).
Report total income on line 1, total deductions on line 2, and taxable income on line 3. Calculate tax on line 4 using the corrected taxable income from line 3, column (c). Complete lines 5 through 11 to determine payments, credits, overpayments, tax dues, or additional overpayments.
Step 5: Attach Supporting Schedules and Forms
If income items changed, attach revised schedules showing dividend income on Schedule C, capital gains and losses on Schedule D, or other income sources. If deduction items changed, attach supporting schedules such as Form 4562 for revised depreciation calculations, amended charitable contribution documentation, or corrected expense allocations.
This checklist is for educational purposes only and does not constitute tax or legal advice. Always review official IRS instructions and consult a qualified professional for guidance.
For net operating loss carryback claims, attach copies of Form 1120, page 1, and the tax computation page for both the year the NOL originated and the carryback year. For eligible small business credit carrybacks, attach documentation supporting the credit calculations and carryback computations.
Step 6: Complete Part I: Explanation of Changes
Provide detailed explanations for each line item changed in Part I. Reference the Part I line number for each adjustment. Describe the reason for each change, such as a mathematical error, receipt of corrected Form 1099, revised depreciation calculation, or correction of reporting classification.
Show all computations supporting the adjustments. If changes involve complex calculations, such as NOL carrybacks, credit carrybacks, or revised tax computations, provide step-by-step calculations that demonstrate how the corrected amounts were determined.
Step 7: Verify Carryback Elections and Procedures
If claiming net operating loss carryback to 2011 or 2010, verify that the loss originated in 2013 and that the carryback is being applied correctly to the earliest year first. If the corporation elects to forego the carryback period for the 2013 NOL, the election cannot be revoked using Form 1120X unless it is made within the statutory time.
If claiming eligible small business credit carryback for five years, verify that the corporation meets the small business definition under section 38(c)(5)(B). Document average annual gross receipts for the three years preceding 2013 to establish qualification. Apply the credit carryback to the earliest eligible year first.
Step 8: Review Schedule M-1 and M-2 Requirements
If amendments affect the reconciliation of book income to taxable income, prepare a revised Schedule M-1. Report federal income tax, excess capital losses, income subject to tax absent from books, expenses recorded on books but not on the return, and income on books but absent from the return.
If amendments impact retained earnings or the balances of other accumulated adjustments accounts, prepare a revised Schedule M-2. Show the beginning balance, net income per book, other increases, distributions, and ending balance. Ensure consistency between the amended Schedule M-2 and the balance sheet adjustments on Schedule L.
This checklist is for educational purposes only and does not constitute tax or legal advice. Always review official IRS instructions and consult a qualified professional for guidance.
Step 9: Verify Filing Deadline Compliance
If claiming a refund, file Form 1120X within three years of the original return's filing date or within two years of the tax payment date, whichever is later. For returns filed before the due date, the filing date is considered to be the due date for purposes of calculating the three-year period.
For NOL carryback claims, file within three years after the due date, including extensions, of the return for the year in which the NOL was incurred. For bad debt or worthless security claims, file within seven years after the due date of the return for the year the debt or security became worthless.
Step 10: Sign, Date, and File
An authorized corporate officer must sign Form 1120X, including the president, vice president, treasurer, assistant treasurer, chief accounting officer, or other duly authorized officer. Include the signer’s title and date of signature. If a receiver, trustee, or assignee files on behalf of the corporation, that fiduciary must sign with supporting documentation of authority.
Mail the completed Form 1120X with all attachments to the IRS service center where the original 2013 Form 1120 was filed. Consult the Where to File instructions for Form 1120X to verify the correct mailing address based on the corporation’s principal business location. Retain copies of the complete amended return and all supporting documentation for the corporation’s records.
Form-Specific Requirements
Form 1120X cannot be filed electronically for the tax year 2013. Paper filing is required. The form must be completed with all three columns correctly filled in for each line being amended. Incomplete forms or those lacking proper explanations in Part II may be rejected or delayed in processing.
If the amendment results in additional tax due, payment should be included with Form 1120X. Make checks payable to the United States Treasury and include the corporation’s name, address, employer identification number, daytime phone number, and tax year on the payment. Interest will accrue on any underpayment from the original due date of the return.
Consolidated Return Considerations
Corporations filing consolidated returns must file consolidated Form 1120X to amend the consolidated return. Each subsidiary corporation included in the consolidated group must be reflected in the amended return. Adjustments to subsidiary income, deductions, or credits must be included in the consolidated Form 1120X.
Intercompany transactions must be eliminated in the consolidated return calculations. Ensure that all eliminations were made correctly on the original consolidated return and that any corrections to intercompany items are appropriately reflected in the amended consolidated return.
Capital Loss Carryback Rules
You can carry back capital losses incurred in 2013 to tax years 2010 and 2011, and carry forward these losses to tax years 2014 through 2018. The capital loss carryback is treated as a short-term capital loss in the carryback year, regardless of whether it was long-term or short-term in the year it was incurred.
If claiming capital loss carryback, attach copies of Form 1120, page 1, and Schedule D for both the year the capital loss was incurred and the carryback year. Show the computation of the capital loss carryback and how it was applied to reduce capital gains in the carryback year.
Amended Schedule K-1 Requirements
If the amended Form 1120X affects items that flow through to shareholders in an S corporation or partners in a partnership, amended Schedule K-1 forms must be issued. While Form 1120X is typically used by C corporations, if the corporation was previously classified differently or if amendments affect related entities, it is essential to coordinate with those entities to ensure proper reporting.
Conclusion
Filing Form 1120X for tax year 2013 requires careful attention to pre-TCJA provisions, graduated corporate tax rates, and proper application of NOL and credit carryback rules. The two-year NOL carryback period and five-year eligible small business credit carryback provision must be appropriately documented and calculated. Adherence to the three-column format, detailed explanations in Part II, and timely filing within statutory deadlines ensure proper processing and prevent loss of refund opportunities.
This checklist is for educational purposes only and does not constitute tax or legal advice. Always review official IRS instructions and consult a qualified professional for guidance.
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This checklist is for educational purposes only and does not constitute tax or legal advice. Always review official IRS instructions and consult a qualified professional for guidance.
