This Schedule O Form 1120 guide explains the IRS Consent Plan and Apportionment Schedule for a Controlled Group. Schedule O for Form 1120 documents the consent plan and apportionment information for the controlled group covered by the instructions. Group membership and the allocation of relevant tax items must follow the applicable definitions and agreement requirements.
Reviewed October 31, 2026. This is an independent guide. The version and availability information below identifies the IRS documents used for this page.
What Schedule O Form 1120 does and who prepares it
A controlled group uses the consent and apportionment schedule when the applicable corporate rules require it.
For the connected reporting route, see Form 1120. Keep the role of that document separate from the task explained on this page.
| Official form | Form 1120 (Schedule O) |
|---|---|
| IRS title | Consent Plan and Apportionment Schedule for a Controlled Group |
| Guide period | the applicable reporting period |
| Target version | Dec 2018 |
| Availability | Current IRS catalog PDF |
| Last checked | October 31, 2026 |
Get the Schedule O Form 1120 PDF and check its status
Use the IRS source to confirm the document before completing a real filing. The download link is a reference to the official file; it is not a statement that every copy inside the PDF may be printed and submitted. Follow any instructions about electronic filing, scannable copies, recipient copies or attachments.
Which version of Schedule O Form 1120 should you use?
This form follows a revision or continuing-use format rather than a new title for every calendar year. Check the revision printed on the document and the period requested inside it. A revision date, transaction date and tax year are different pieces of information. The current document should be read with the instructions that apply to the actual transaction or return.
Records to gather for Schedule O Form 1120
- Controlled group ownership records.
- Member corporation information.
- Consent plan.
- Apportionment workpapers.
- Member returns.
Keep a working reconciliation with these records. It should show the source of each reported item, any correction made before filing and the reason a different amount appears on a connected form. This is especially useful when a statement is corrected or a prior-year balance continues into the current calculation.
How to work through Schedule O Form 1120
- Confirm applicability. Start with the purpose, filer category and version of the form. Complete any eligibility or applicability question before spending time on the numerical calculation.
- Prepare the source workpapers. Gather the records listed below and reconcile their totals. Keep prior-year balances, current-year transactions and estimated payments separate where they serve different purposes.
- Complete dependent calculations first. When a line refers to another form, schedule or worksheet, finish that supporting calculation first. Preserve any classification, limitation and carryforward information.
- Follow the line sequence. Use the actual line labels and arithmetic in the applicable form. A line number from an older version may refer to something different after a revision.
- Reconcile the filing package. Check names, identifying numbers, tax periods, totals and required attachments. Then use the filing method, signature process and deadline that apply to this filer and form.
Form-specific IRS instructions and reporting details
The following points retain the operative wording of the IRS documents linked above. Read each point with its stated conditions and the applicable form version. References to another form or section describe a connected requirement; they do not mean that every reader must file every referenced document.
Schedule O (Form 1120) and the 1120) have been revised to reflect the replacement of the graduated corporate tax structure with a flat 21% corporate tax rate and the repeal of the corporate alternative minimum tax. These changes are effective for tax years beginning after December 31, 2017.
A corporation that is a component member (defined below) of a controlled group must use Schedule O to report the apportionment of certain tax benefits between all component members of the group. These members will be subject to limitations on the use of certain tax benefits for their applicable tax year. See Apportionment of tax-benefit items, later.
• Have no apportionment plan in effect and are not adopting an apportionment plan; or • Already have an apportionment plan in effect. Use Schedule O (Form 1120) (Rev. December 2012) to amend an existing apportionment plan for tax years beginning before January 1, 2018.
A corporation must file Schedule O with its income tax return, amended return, or claim for refund for each tax year that the corporation is a component member of a controlled group, even if (1) no apportionment plan is in effect, or (2) the amounts apportioned have not changed from the previous tax year. See Definitions and Special Rules, later.
Additional reporting conditions
Consolidated groups. If any of the component members of a controlled group also are members of a consolidated group, then the common parent of that consolidated group must file, as part of its consolidated income tax return, one Schedule O on behalf of the members of that consolidated group. No subsidiary of that consolidated group should file Schedule O on its own behalf. The Schedule O should contain the required consolidated information for all members of the consolidated group. See Identifying Information, later. Exception.
If all of the members of a parent–subsidiary controlled group that are required to file a U.S. tax return join in filing the same consolidated tax return, then the parent of that group does not have to file Schedule O on behalf of the group.
Calculations and supporting information
• The filing of Schedule O by a component member provides the required information as to the status of the group's apportionment plan.
Such information must indicate, when applicable, whether all the component members of the controlled group are adopting, amending, or terminating an apportionment plan. • If all such members complete the required written agreement setting forth the terms of the adopted or amended apportionment plan or an agreement to terminate a previously adopted plan, then each member of that group may rely on this agreement as the member's basis for representing on its Schedule O that the other component members of the group also have consented to adopting, amending, or terminating the apportionment plan. • The agreement must be signed by a person authorized to sign on behalf of each component member of the controlled group and retained.
No member should attach this agreement (or a copy of it) to their federal income tax returns. Each component member must keep, as part of its records, either the original or a copy of the signed agreement. The agreement must contain the group's apportionment methodology (for example, percentages) for each tax-benefit item that is apportioned.
Exceptions and related reporting
December 31 date, the last day of its short tax year is deemed to function as the December 31 testing date for that member only. For a member on a full fiscal tax year, the portion of its tax year beginning on the December 31 testing date and ending on the last day of its tax year is not taken into account for determining its status either as a component member or as an excluded member.
In determining how many days comprise a member's testing period, the group takes into account the day that the member is sold, but does not take into account either the day that such member is acquired or the member's December 31 testing date.
If a corporation is a component member of more than one controlled group with respect to any tax year, that corporation will be treated as a component member of only one controlled group. The determination as to the group of which such corporation is a component member will be made under regulations prescribed by the Secretary.
To be a member of a controlled group, a corporation cannot be connected through stock ownership based on “excluded stock.” Excluded stock includes: • Nonvoting stock which is limited and preferred as to dividends, • Treasury stock, and • Stock which is treated as excluded stock under section 1563(c)(2)(A) for a parent–subsidiary controlled group or section 1563(c)(2)(B) for a brother– sister controlled group.
Further form details
An apportionment plan is an agreement between the component members of a controlled group for apportioning certain corporate tax benefits among the members of that group. By contrast, a tax-sharing agreement is an agreement entered into between members of an affiliated group of corporations which have joined in the filing of a consolidated tax return. Such an agreement generally provides that the members of the affiliated group will compensate each other for certain tax benefits incurred by members separately and shared by all members on the consolidated tax return.
This corporation consents and represents to: Adopt an apportionment plan. All the other members of this group are adopting an apportionment plan effective for the , and for all succeeding tax years. current tax year which ends on , 20 b Amend the current apportionment plan. All the other members of this group are currently amending a previously adopted , and for all succeeding tax years. plan, which was in effect for the tax year ending , 20 c Terminate the current apportionment plan and not adopt a new plan.
All the other members of this group are not adopting an apportionment plan. d Terminate the current apportionment plan and adopt a new plan. All the other members of this group are adopting an , and for all apportionment plan effective for the current tax year which ends on , 20 succeeding tax years.
Further form details
If you did not check a box on line 3 above, check the applicable box below concerning the status of the group’s apportionment plan (see instructions). a No apportionment plan is in effect and none is being adopted. b , and for An apportionment plan is already in effect. It was adopted for the tax year ending , 20 all succeeding tax years.
Reading the lines and boxes
These selected labels come from the linked target PDF. They are a reading aid, not a replacement for the full line instructions or a completed calculation. Match the label and document version before transferring any amount.
| Line or box | Label in the source form | What to check |
|---|---|---|
| 1 | Type of controlled group: | Check the applicable line instructions and keep the source workpaper with the return records. Transfer only the information that matches the field and reporting period. |
| 2 | This corporation has been a member of this group: | Check the applicable line instructions and keep the source workpaper with the return records. Transfer only the information that matches the field and reporting period. |
| 3 | This corporation consents and represents to: | Check the applicable line instructions and keep the source workpaper with the return records. Transfer only the information that matches the field and reporting period. |
| 4 | If you checked box 3c or 3d above, check the applicable box below to indicate if the termination of the current apportionment | Check the applicable line instructions and keep the source workpaper with the return records. Transfer only the information that matches the field and reporting period. |
| 5 | If you did not check a box on line 3 above, check the applicable box below concerning the status of the group’s apportionment | Check the applicable line instructions and keep the source workpaper with the return records. Transfer only the information that matches the field and reporting period. |
Further selected fields
| Line or box | Label in the source form | What to check |
|---|---|---|
| 6 | If all the members of this group are adopting a plan or amending the current plan for a tax year after the due date | Use the date or tax period requested by this particular field. A payment date, acquisition date and return year can describe different facts. |
A practical example
A group of corporations prepares its returns and reviews the controlled-group requirements. The preparers reconcile the member details and supported apportionment information before submitting the required schedules.
This example illustrates the order of the review. It does not assume an unverified deduction, exemption, treaty rate or final tax amount. The applicable form instructions and the actual records determine the result.
Common mistakes to avoid with Schedule O Form 1120
- Confirm group membership under the tax rules.
- Do not invent allocations without the required plan and support.
- Keep member schedules and return reporting consistent.
Questions about Schedule O Form 1120
Does receiving or downloading this form mean I must file it?
A controlled group uses the consent and apportionment schedule when the applicable corporate rules require it. The form purpose and the applicable filing or furnishing conditions determine the action. Downloading a blank PDF does not itself create a filing obligation or establish eligibility for a tax benefit.
Is the revision date always the same as the tax year?
No. Some forms show a tax year, while continuing-use forms show a revision date and ask separately for the reporting period. Check the actual document and instructions. Do not relabel a payment or transaction solely because it was reported in a later calendar year.
What should I do if the underlying information is wrong?
Confirm group membership under the tax rules. Keep the original record and the correction trail. The issuer correction process, an amended return and an updated certificate can be different procedures. Choose the process that matches the document and the actual error.
Which records should I keep with the completed form?
Retain the source documents, applicable worksheets, submitted version and filing or furnishing confirmations. For this form, the working file should include controlled group ownership records, member corporation information, consent plan. Keep continuing balances and prior-year support for as long as they remain relevant under the applicable recordkeeping rules.
Related forms and next steps
Use these guides when the connected issue applies to your records. Each page has its own purpose, reporting year and availability status.