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Form 172: Net Operating Losses (NOLs)
IRS Form 172 is used to compute and report a net operating loss (NOL) deduction for corporations, estates, and trusts. The form calculates the carryback and carryover years, but no specific thresholds, rates, or deadlines are provided in the available source.
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IRS Form 172 - Net Operating Losses (NOLs)
IRS Form 172 is used to compute and report a net operating loss (NOL) deduction for corporations, estates, and trusts. The form calculates the carryback and carryover years, but no specific thresholds, rates, or deadlines are provided in the available source.
Risk Radar
Scan points- 1Failing to attach Form 172 to your tax return could result in loss of the NOL deduction.
- 2Not including all NOL carryovers from prior years in Part II
- 3Using the wrong year's NOL amount for the carryback or carryforward
- 4Failing to attach Form 172 to the tax return as required
- 5Entering a negative number instead of a positive NOL amount
Plain English
This form helps businesses and trusts figure out how much of a past loss they can use to lower their taxes this year. It shows which years the loss can be carried back to or carried forward. You fill it out and attach it to your tax return.
Submission Date
- Filing date: 2025-01-16 22:10:20
- Preparation window: collect IDs, supporting records, and signatures in advance.
- Final review: verify names, dates, and required fields before submission.
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What this form is for
- Use this form when you are a corporation, estate, or trust and need to compute and report a net operating loss (NOL) deduction for the current tax year.
- Do not use it when you are an individual claiming an NOL deduction; individuals generally use Form 1045 or Form 1040 instead.
- Check Form 1045 (Application for Tentative Refund) instead when you are an individual or a corporation seeking a quick refund based on an NOL carryback.
Form selector
Use this form or another form?
An estate or trust reports NOL deduction on line 15b, but the calculation requires an entity-level adjustment
Beneficiary share of NOL is reported on K-1, not directly on Form 172
✓ The estate must file Form 1041 separately before completing Form 172
A corporation carries NOL back to a prior tax year to claim refund
Faster refund than filing amended return; Form 172 provides the NOL amount needed for line 8 of Form 1139
✓ Confirm the carryback period in current tax law before filing Form 1139
Form 1139 (Corporation Application for Tentative Refund)
An estate carries NOL back to reduce prior-year income
Quick refund processing for non-corporate entities; Form 172 supplies the NOL deduction for line 5 of Form 1045
✓ Review whether the NOL is subject to the 80% taxable income limitation for carryovers
Form 1045 (Application for Tentative Refund)
Deadline or filing window
Not stated in the official source.
Checklist
What you need before filling it out
Part I – NOL Deduction
Completed Form 172 showing NOL amount · IRS Form 172 instructions for line 1
Line 2 – NOL carryover from prior years
Prior year tax return and supporting NOL schedules · IRS Form 172 instructions for line 2
Part II – NOL Computation
Trial balance or P&L statement showing operating loss · IRS Form 172 instructions for Part II
Line 8 – Modified taxable income
Computation of taxable income after adjustments for NOL carryback · IRS instructions for Form 172 and IRC Section 172(d)
Signature block
Authorized signer, date, and preparer's PTIN or SSN · IRS Form 172 page 2
Attached schedule for NOL carryover
Detailed listing of each NOL year and amounts · IRS Form 172 instructions for line 2
Applicable corporate tax return (e.g., Form 1120)
Final net operating loss figure from Schedule C or M-1 · IRS Form 1120 instructions
Before you submit
- 1Confirm the form revision date matches the current tax year.
- 2Fill in taxpayer name and identifying number exactly as on the tax return.
- 3Enter the tax year end date for which the NOL is claimed.
- 4Compute the NOL deduction amount correctly using the worksheet or instructions.
- 5Attach any required schedules or supporting documentation (e.g., prior year returns).
- 6Verify carryback or carryforward years are correctly identified and calculated.
- 7Sign and date the form (if required) — see instructions for signature rules.
- 8Make a copy of the completed form and all attachments for your records.
- 9Mail the form to the correct IRS address for your entity type and location — confirm on the IRS website.
- 10Send the form by a trackable method (e.g., certified mail) if proof of receipt is needed.
How to file this form
- 1Obtain the current version of IRS Form 172 from the IRS website.
- 2Read the instructions for Form 172 carefully to understand the NOL deduction rules.
- 3Gather all necessary financial records, including prior year tax returns and NOL worksheets.
- 4Complete the taxpayer identification information at the top of the form.
- 5Fill in the NOL deduction calculation following the form's line-by-line instructions.
- 6Attach any required schedules or documentation, such as a statement detailing the NOL computation.
- 7Sign the form if required (per instructions, check the signature line).
- 8Mail the completed form to the appropriate IRS address or file electronically if permitted — confirm the method on the IRS website.
Known limitations
- 1The available source does not specify any exceptions or special rules — verify all limitations on the IRS website.
- 2This form is not used by individual taxpayers; they must use Form 1045 or Form 1040 instead.
- 3This form may not apply to NOLs from activities that are not trade or business losses (e.g., casualty losses for individuals).
- 4Special rules may apply for tax-exempt entities, regulated investment companies, or real estate investment trusts — check IRS guidance.
Field map
Compact field-by-field guide
General Info
2 items
Full legal name and taxpayer identification number (SSN or EIN).
Current mailing address.
Details
2 items
Complete all applicable sections of this form according to the official IRS instructions.
Enter the relevant dollar amount if this form involves tax calculation.
Certification
1 items
Read and acknowledge any certifications required by this form.
Signatures
1 items
Sign and date. Unsigned forms cannot be processed.
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Fillable formOpen in Editor->The available source does not specify a revision date, a latest information page, or any changes. Confirm the edition on the IRS website before using the form.
What changed or needs a fresh check
- Edition date — Not stated in the official source — verify on the agency site.
- Fee — Not stated in the official source — verify on the agency site.
- Mailing address — Not stated in the official source — verify on the agency site.
- Signature — Not stated in the official source — verify on the agency site.
- Proof of filing — Not stated in the official source — verify on the agency site.
Quick Facts
Downloads
After you file
- 1Retain a copy of the filed Form 172 and all attachments for at least 7 years.
- 2Note the date of mailing and any tracking number for documentation.
- 3Monitor IRS account transcripts or correspondence for confirmation of processing.
- 4If you do not receive any acknowledgment within 60 days, contact the IRS via the appropriate phone number or address.
- 5If an error is discovered after filing, file an amended return (e.g., Form 1120X or Form 1041) to correct the NOL deduction.
- 6Keep records of any IRS notices related to the NOL deduction or carryback adjustments.
Sources
- SRCNot stated in the official source — verify on the agency site.
- SRCNot stated in the official source — verify on the agency site.
- SRCNot stated in the official source — verify on the agency site.
- SRCNot stated in the official source — verify on the agency site.
- SRCNot stated in the official source — verify on the agency site.
- SRCNot stated in the official source — verify on the agency site.
- SRCNot stated in the official source — verify on the agency site.
- SRCNot stated in the official source — verify on the agency site.
- SRCNot stated in the official source — verify on the agency site.
- SRCNot stated in the official source — verify on the agency site.
Common confusion points
Do I need a separate form for each NOL year?
Form 172 allows consolidating multiple NOL years on a single form, but each year must be listed separately on the schedule
→ Use the approved schedule format in the IRS instructions; attach one detailed list by year
Can I use Form 172 for both carryback and carryover?
Yes, both types are reported on the same form but need distinct line entries for carryback and carryover
→ Read Part I lines 1–4 and Full-year NOL carryover schedule; separate carryback and carryover amounts
What if my NOL is from a pass-through entity?
Pass-through losses flow to the individual or entity owner, who reports them on their own Form 172, not the entity
→ The owner's K-1 will show the NOL amount, and the owner files Form 172 using that number
Is Form 172 required even if I zero out the NOL this year?
Yes, the form computes the allowed deduction for the current year; filing is mandatory to document the use of the loss
→ Complete Part I lines 1–8; if no carryover remains, write zero on line 2
Does a late-filed Form 172 change my NOL deduction?
The NOL deduction is computed on the return for the year the loss is used; filing Form 172 late does not change the allowed deduction but may affect the carryover schedule
→ File Form 172 with the original or amended return for the year you claim the deduction
Can I e-file Form 172?
Yes, most tax software supports e-filing Form 172 as a supporting schedule attached to the corporate or fiduciary return
→ Confirm your software lists Form 172 under the applicable return; otherwise attach PDF or paper file
Workflow map
Related forms and next steps
Before
Current
After
Often used with
⚠ If something goes wrong
- Form 843 — Claim for Refund and Request for Abatement, if IRS disputes the NOL deduction.
Questions about IRS Form 172
What is IRS Form 172 used for?
This form helps businesses and trusts figure out how much of a past loss they can use to lower their taxes this year. It shows which years the loss can be carried back to or carried forward. You fill it out and attach it to your tax return.
Who must file IRS Form 172?
Corporations, estates, and trusts that have a net operating loss deduction must file Form 172. The filer must also attach a completed Form 172 to their tax return for the year of the deduction.
What information does IRS Form 172 require?
Form 172 collects the amount of the net operating loss, the NOL carryover from prior years, and the NOL carryback to prior years. It also includes a schedule showing the NOL deduction for the current tax year.
How do I complete IRS Form 172?
Complete Part I to compute the NOL for the tax year. Then in Part II, list any NOL carryovers and carrybacks from other years. Finally, enter the total NOL deduction on the appropriate line of your tax return. Sign and date the form before attaching it to your return.
Do I need a separate form for each NOL year?
Form 172 allows consolidating multiple NOL years on a single form, but each year must be listed separately on the schedule Use the approved schedule format in the IRS instructions; attach one detailed list by year
Can I use Form 172 for both carryback and carryover?
Yes, both types are reported on the same form but need distinct line entries for carryback and carryover Read Part I lines 1–4 and Full-year NOL carryover schedule; separate carryback and carryover amounts
What if my NOL is from a pass-through entity?
Pass-through losses flow to the individual or entity owner, who reports them on their own Form 172, not the entity The owner's K-1 will show the NOL amount, and the owner files Form 172 using that number
Is Form 172 required even if I zero out the NOL this year?
Yes, the form computes the allowed deduction for the current year; filing is mandatory to document the use of the loss Complete Part I lines 1–8; if no carryover remains, write zero on line 2
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