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Blank Illinois 1120 Form

The Illinois 1120 form is the Corporation Income and Replacement Tax Return required by the Illinois Department of Revenue. This form is essential for corporations operating in Illinois to report their income and calculate their tax obligations. Timely and accurate filing is crucial to avoid penalties and ensure compliance with state tax laws.

Outline

The Illinois 1120 form is a crucial document for corporations operating within the state, serving as the Corporation Income and Replacement Tax Return. This form is specifically designed for tax years ending on or after December 31, 2020, and before December 31, 2021. It requires businesses to report their income, deductions, and tax obligations accurately. Key sections of the form include identifying the corporation, detailing income or loss, and calculating the net income tax and replacement tax after credits. Additionally, corporations must provide information such as their legal business name, federal employer identification number, and accounting records location. The form also addresses various scenarios, like if it’s the first or final return, and includes sections for apportionment formulas and additional schedules that may need to be attached. Understanding the structure and requirements of the Illinois 1120 form is essential for compliance and ensuring that all necessary information is provided to avoid penalties.

Sample - Illinois 1120 Form

Illinois Department of Revenue	63512211W
2021 Form IL-1120

Corporation Income and Replacement Tax Return

See “When should I file?” in the Form IL-1120 instructions for a list of due dates.

If this return is not for calendar year 2021, enter your fiscal tax year here.

Tax year beginning		20	, ending		20

	month day		year	month day		year

This form is for tax years ending on or after December 31, 2021, and before December 31, 2022. For all other situations, see instructions to determine the correct form to use.

Enter the amount you are paying.

$ _______________________

Step 1: Identify your corporation

AEnter your complete legal business name. If you have a name change, check this box.

Name:

BEnter your mailing address.

Check this box if either of the following apply:

•this is your ﬁrst return, or

•you have an address change.

C/O:	__________________________________________________
Mailing address:		___________________________________________
City:			State:	ZIP:

CIf this is the first or final return, check the applicable box(es).

First return
Final return (Enter the date of termination.			)
	mm dd	yyyy

DIf this is a final return because you sold this business, enter the date sold

(mm dd yyyy)

, and the new owner’s FEIN.

ECheck the box and see the instructions if your business is a:

Unitary Filer (Combined return)

Foreign insurer

FIf you completed the following, check the box and attach the federal

form(s) to this return.

Federal Form 8886 Federal Schedule M-3, Part II, Line 12

GApportionment Formulas. Mark the appropriate box or boxes and see

Apportionment Formula instructions.	Sales companies
Insurance companies	Financial organizations
Transportation companies	Federally regulated exchanges

H Check this box if you attached Illinois Schedule UB.

I Check this box if you attached the Subgroup Schedule.

J Check this box if you attached Illinois Schedule 1299-D.

K Check this box if you attached Form IL-4562.

L Check this box if you attached Illinois Schedule M (for businesses). M Check this box if you attached Schedule 80/20.

NEnter your federal employer identification number (FEIN).

OIf you are a member of a group filing a federal consolidated return, enter the FEIN of the parent.

PEnter your North American Industry Classification System (NAICS) Code. See instructions.

QEnter your corporate file (charter) number assigned to you by the Secretary of State.

REnter the city, state, and zip code where your accounting records are kept. (Use the two-letter postal abbreviation, E.G., IL, GA, etc.)

City

State

ZIP

SIf you are making the business income election to treat all nonbusiness income as business income, check this box and enter zero on Lines 24 and 32.

TCheck your method of accounting.

Cash Accrual Other

UIf you are making a discharge of indebtedness adjustment on Form IL-1120, Line 36, check this

box and attach federal Form 982 and a detailed statement.

VCheck this box if you attached Schedule INL.

WIf you annualized your income on Form IL-2220,

check this box and attach Form IL-2220.

XCheck this box if your business activity is protected under Public Law 86-272.

Y Check this box if you are a 52/53 week filer.

Attach your payment and Form IL-1120-V here.

If you owe tax on Line 67, make an electronic payment at Tax.Illinois.gov. If you must mail your payment, complete a payment voucher, Form IL-1120-V. Write your FEIN, tax year ending, and “IL-1120-V” on your check or money order and make it payable to “Illinois Department of Revenue.” Attach your voucher and payment here.

Enter the amount of your payment on the top of this page in the space provided.

If a payment is not enclosed, mail this return to:	If a payment is enclosed, mail this return to:
ILLINOIS DEPARTMENT OF REVENUE	ILLINOIS DEPARTMENT OF REVENUE
PO BOX 19048	PO BOX 19038
SPRINGFIELD IL 62794-9048	SPRINGFIELD IL 62794-9038

	This form is authorized as outlined by the Illinois Income Tax Act. Disclosure of this	IR	NS	DR ____
Page 1 of 4	information is REQUIRED. Failure to provide information could result in a penalty.			IL-1120 (R-12/21)
Page 1 of 4				IL-1120 (R-12/21)

*63512212W*

Step 2: Figure your income or loss

(Whole dollars only)

1Federal taxable income from U.S. Form 1120, Line 30.

	Attach a copy of your federal return.		1	00
2	Net operating loss deduction from U.S. Form 1120, Line 29a. This amount cannot be negative.		2	00
3	State, municipal, and other interest income excluded from Line 1.		3	00
4	Illinois income and replacement tax and surcharge deducted in arriving at Line 1.		4	00
5	Illinois Special Depreciation addition. Attach Form IL-4562.		5	00
6	Related-Party Expenses additions. Attach Schedule 80/20.		6	00
7	Distributive share of additions. Attach Schedule(s) K-1-P or K-1-T.		7	00
8	Other additions. Attach Schedule M (for businesses).		8	00
9	Add Lines 1 through 8. This amount is your income or loss.		9	00

Step 3: Figure your base income or loss
10	Interest income from U.S. Treasury and other exempt federal obligations.	10	00

11River Edge Redevelopment Zone Dividend subtraction.

Attach Schedule 1299-B.

12River Edge Redevelopment Zone Interest subtraction.

	Attach Schedule 1299-B.	12		00
13	High Impact Business Dividend subtraction. Attach Schedule 1299-B.	13		00
14	High Impact Business Interest subtraction. Attach Schedule 1299-B.	14		00
15	Contribution subtraction. Attach Schedule 1299-B.	15		00
16	Contributions to certain job training projects. See instructions.	16		00
17	Foreign Dividend subtraction. Attach Schedule J. See instructions.	17		00
18	Illinois Special Depreciation subtraction. Attach Form IL-4562.	18		00
19	Related-Party Expenses subtraction. Attach Schedule 80/20.	19		00
20	Distributive share of subtractions. Attach Schedule(s) K-1-P or K-1-T.	20		00
21	Other subtractions. Attach Schedule M (for businesses).	21		00	00
22	Total subtractions. Add Lines 10 through 21.		22		00
23	Base income or loss. Subtract Line 22 from Line 9.		23		00

AIf the amount on Line 23 is derived inside Illinois only, check this box and enter the amount from Step 3, Line 23 on Step 5, Line 35. You may not complete Step 4. (You must leave Step 4, Lines 24 through 34 blank.)

If you are a unitary ﬁler, do not check this box. Check the box on Line B and complete Step 4.

B If any portion of the amount on Line 23 is derived outside Illinois, or you are a unitary ﬁler, check this box and complete all lines of Step 4. (Do not leave Lines 28 through 30 blank.) See instructions.

Step 4: Figure your income allocable to Illinois	(Complete only if you checked the box on Line B, above.)
24 Nonbusiness income or loss. Attach Schedule NB.	24		00

25Business income or loss included in Line 23 from non-unitary partnerships, partnerships included on a Schedule UB, S corporations, trusts,

	or estates. See instructions.	25		00
26	Add Lines 24 and 25.		26			00
27	Business income or loss. Subtract Line 26 from Line 23.		27		00
28	Total sales everywhere. This amount cannot be negative.	28
29	Total sales inside Illinois. This amount cannot be negative.	29
30	Apportionment Factor. Divide Line 29 by Line 28. Round to six decimal places.	30
31	Business income or loss apportionable to Illinois. Multiply Line 27 by Line 30.		31			00
32	Nonbusiness income or loss allocable to Illinois. Attach Schedule NB.		32			00

33Business income or loss apportionable to Illinois from non-unitary partnerships, partnerships

included on a Schedule UB, S corporations, trusts, or estates. See instructions.	33		00
34 Base income or loss allocable to Illinois. Add Lines 31 through 33.	34		00

Page 2 of 4

Printed by the authority of the state of Illinois. Web only, one copy.

IL-1120 (R-12/21)

Step 5: Figure your net income

*63512213W*

35Base income or net loss from Step 3, Line 23, or Step 4, Line 34.

36Discharge of indebtedness adjustment. Attach federal Form 982. See instructions.

37Adjusted base income or net loss. Add Lines 35 and 36. See instructions.

38Illinois net loss deduction. If Line 37 is zero or a negative amount, enter zero. Check this box and attach a detailed statement if you have merged losses.

39Net income. Subtract Line 38 from Line 37.

3500

3600

3700

3800

3900

Step 6: Figure your replacement tax after credits

40	Replacement tax. Multiply Line 39 by 2.5% (.025).	40
41	Recapture of investment credits. Attach Schedule 4255.	41
42	Replacement tax before credits. Add Lines 40 and 41.	42
43	Investment credits. Attach Form IL-477.	43
44	Replacement tax after credits. Subtract Line 43 from Line 42. If the amount is negative, enter zero.	44

Step 7: Figure your income tax after credits

45	Income tax. Multiply Line 39 by 7.0% (.07).		45	00
46	Recapture of investment credits. Attach Schedule 4255.		46	00
47	Income tax before credits. Add Lines	45 and 46.	47	00
48	Income tax credits. Attach Schedule	1299-D.	48	00
49	Income tax after credits. Subtract Line 48 from Line 47. If the amount is negative, enter zero.		49	00

Step 8: Figure your refund or balance due

50Replacement tax before reductions. Enter the amount from Line 44.

51Foreign Insurer replacement tax reduction. Attach Schedule INS or UB/INS. See instructions.

52Subtract Line 51 from Line 50. This is your net replacement tax.

53Income tax before reductions. Enter the amount from Line 49.

54Foreign Insurer income tax reduction. Attach Schedule INS or UB/INS. See instructions.

55Subtract Line 54 from Line 53. This is your net income tax.

56Compassionate Use of Medical Cannabis Program Act surcharge. See instructions.

57Sale of assets by gaming licensee surcharge. See instructions.

58Total net income and replacement taxes and surcharges. Add Lines 52, 55, 56, and 57.

59Underpayment of estimated tax penalty from Form IL-2220. See instructions.

60Total taxes, surcharges, and penalty. Add Lines 58 and 59.

61Payments. See instructions.

a	Credits from previous overpayments.	61a
b	Total payments made before the date this return is filed.	61b

cPass-through withholding reported to you.

	Attach Schedule(s) K-1-P or K-1-T.	61c
d	Pass-through entity tax credit reported to you.
	Attach Schedule(s) K-1-P or K-1-T.	61d
e	Illinois income tax withholding. Attach Form(s) W-2G.	61e

62Total payments. Add Lines 61a through 61e.

63Overpayment. If Line 62 is greater than Line 60, subtract Line 60 from Line 62.

64Amount to be credited forward. See instructions.

Check this box and attach a detailed statement if this carryforward is going to a different FEIN.

65Refund. Subtract Line 64 from Line 63. This is the amount to be refunded.

66Complete to direct deposit your refund.

Routing Number

Checking or

Savings

Account Number

5000

5100

5200

5300

5400

5500

5600

5700

5800

5900

6000

6200

63 00

64 00

6500

67 Tax due. If Line 60 is greater than Line 62, subtract Line 62 from Line 60. This is the amount you owe.		67		00

Step 9: Sign below - Under penalties of perjury, I state that I have examined this return and, to the best of my knowledge, it is true, correct and complete.

Sign			(	)		Check if the Department
Here					may discuss this return with the
	Signature of authorized officer	Date (mm/dd/yyyy) Title	Phone		paid preparer shown in this step.

Paid				Check if
	Print/Type paid preparer’s name	Paid preparer’s signature	Date (mm/dd/yyyy)	self-employed		Paid Preparer’s PTIN
Preparer
	Firm’s name		Firm’s FEIN
Use Only

	Firm’s address		Firm’s phone		(	)

Page 3 of 4

Enter the amount of your payment in the space provided on the top of page 1.

IL-1120 (R-12/21)

Attach supporting documents to your Form IL-1120.

*ZZZZZZZZZ*

If you completed:

Attach:

Form IL-1120

U.S. 1120, Pages 1 through 6, or equivalent

Step 1, Line E (unitary) only

Schedule UB/Subgroup Schedule

Check the box on Form IL-1120, Step 1, Line H

Step 1, Line E (foreign insurer) only

Schedule INS

Step 1, Line E (unitary) and (foreign insurer)

Schedule UB/Subgroup Schedule and Schedule UB/INS

Check the box on Form IL-1120, Step 1, Line H

Step 1, Line F

Federal Form 8886 or Federal Schedule M-3 (as applicable)

Step 1, Line U

Federal Form 982

Step 1, Line V

Schedule INL

Step 1, Line W

Form IL-2220

Lines 5 and 18

Form IL-4562

Special Depreciation addition

Check the box on Form IL-1120, Step 1, Line K

Special Depreciation subtraction

Lines 6 and 19

Schedule 80/20

Related-Party Expenses addition

Check the box on Form IL-1120, Step 1, Line M

Related-Party Expenses subtraction

Lines 7 and 20

Schedule(s) K-1-P or K-1-T

Distributive share of additions

Distributive share of subtractions

Lines 8 and 21

Schedule M and any required support listed on Schedule M

Other additions

Check the box on Form IL-1120, Step 1, Line L

Other subtractions

Lines 11 through 15

Schedule 1299-B and any required support listed on Schedule

River Edge Redevelopment Zone

1299-B

Dividend subtraction

River Edge Redevelopment Zone

Interest subtraction

High Impact Business Dividend subtraction

High Impact Business Interest subtractions

Contributions subtraction

Line 17

Foreign Dividend Subtraction

Illinois Schedule J, and U.S. 1120, Schedule C or equivalent

Lines 24 and 32

Schedule NB

Nonbusiness income or loss

Nonbusiness income or loss allocable to Illinois

Lines 25 and 33

Schedule(s) K-1-P or K-1-T

Business income or loss from non-unitary

partnerships, partnerships included on a Schedule UB,

S corporations, trusts, or estates

Business income or loss apportionable to Illinois from

non-unitary partnerships, partnerships included on a

Schedule UB, S corporations, trusts, or estates

Line 36 Discharge of indebtedness adjustment

Federal Form 982

Check the box on Form IL-1120, Step 1, Line U

Lines 41 and 46 Recapture of investment credit

Schedule 4255

Line 43

Investment credits

Form IL-477 and any required support listed on Form IL-477

Line 48

Income tax credits

Schedule 1299-D and any required support listed in the Schedule

1299-D instructions or Schedule 1299-I

Check the box on Form IL-1120, Step 1, Line J

Lines 51 and 54 Foreign Insurer tax reduction

Schedule INS or Schedule UB/INS (for unitary filers)

Check the box on Form IL-1120, Step 1, Line E

Line 59

Underpayment of estimated tax penalty

Form IL-2220

If you annualized your income on Form IL-2220, Step 6,

check the box on Form IL-1120, Step 1, Line W

Line 61c

Pass-through withholding reported

All Schedules K-1-P and K-1-T you received showing

to you

pass-through withholding

Line 61d Pass-through entity tax credit

All Schedules K-1-P and K-1-T you received showing

reported to you

pass-through entity tax credit

Line 61e Illinois income tax withholding

Copies of all Forms W-2G

**Failure to attach the required documents may result in the disallowance of the corresponding line item.**

Page 4 of 4

IL-1120 (R-12/21)

Click for PDF

Form Information

Fact Name	Description
Purpose of the Form	The Illinois 1120 form is used by corporations to report income and calculate the replacement tax for the state of Illinois.
Filing Period	This form is specifically for tax years ending on or after December 31, 2020, and before December 31, 2021.
Governing Law	The form is authorized under the Illinois Income Tax Act, which outlines the requirements for corporate income tax in the state.
Filing Requirements	Corporations must file the IL-1120 by the due date specified in the instructions, which varies based on the corporation's fiscal year.
Payment Instructions	If tax is owed, payments can be made electronically or via mail using Form IL-1120-V, which must accompany the payment.

Detailed Guide for Filling Out Illinois 1120

Completing the Illinois 1120 form is an important task for corporations operating in the state. This process involves several steps that require attention to detail. It is essential to gather all necessary information and documentation before starting, as this will help ensure a smooth completion of the form.

Identify Your Corporation: Fill in your complete legal business name. If there has been a name change, check the corresponding box.
Provide your mailing address. Check the box if this is your first return or if there has been an address change.
If applicable, indicate whether this is your first or final return by checking the appropriate box(es) and entering the date of termination if it is a final return.
For final returns due to the sale of the business, enter the date sold and the new owner’s FEIN.
If your business qualifies, check the box for Unitary Filer, Foreign insurer, or if you are attaching federal forms like Form 8886 or Schedule M-3.
Complete any necessary apportionment formulas by marking the appropriate boxes.
Enter your federal employer identification number (FEIN) and, if applicable, the FEIN of the parent company if part of a group filing a federal consolidated return.
Provide your North American Industry Classification System (NAICS) Code and corporate file number assigned by the Secretary of State.
Indicate where your accounting records are kept by entering the city, state, and zip code.
Check your method of accounting: Cash, Accrual, or Other.
If making a discharge of indebtedness adjustment, check the box and attach the required federal form.
Attach any necessary schedules and forms as indicated in the instructions.

Figure Your Income or Loss: Start with your federal taxable income from U.S. Form 1120, Line 30, and attach a copy of your federal return.
Include the net operating loss deduction from U.S. Form 1120, Line 29a, ensuring this amount is not negative.
List state, municipal, and other interest income excluded from your federal taxable income.
Deduct any Illinois income and replacement tax and surcharge from your federal taxable income.
Add any Illinois Special Depreciation and Related-Party Expenses, and include distributive shares of additions.
Calculate your total income or loss by adding these amounts together.

Figure Your Base Income or Loss: List any exempt interest income and various subtractions, such as contributions and foreign dividends.
Calculate your total subtractions and determine your base income or loss by subtracting total subtractions from your total income or loss.

Figure Your Income Allocable to Illinois: Complete this step only if any portion of your income is derived outside Illinois.
List any nonbusiness income or loss and business income or loss from partnerships or S corporations.
Calculate your apportionment factor and determine the income allocable to Illinois.

Figure Your Net Income: Start with your base income or net loss and add any discharge of indebtedness adjustments.
Calculate your net income by subtracting any Illinois net loss deductions.

Figure Your Replacement Tax After Credits: Multiply your net income by 2.5% to determine your replacement tax.
Account for any recapture of investment credits and calculate your replacement tax after credits.

Figure Your Income Tax After Credits: Calculate your income tax and any recapture of investment credits.
Determine your income tax after credits by subtracting the credits from your total income tax before credits.

Figure Your Refund or Balance Due: Calculate your total taxes, surcharges, and penalties.
Determine your total payments and overpayment if applicable.
Complete the section for directing deposit of your refund if you are owed one.
Finally, determine the amount due if applicable.

Sign and Date the Form: An authorized officer must sign the form, stating that all information is true and complete.
Include any required attachments and supporting documents as specified in the instructions.

Once the form is completed, ensure all necessary documentation is attached. Review the instructions for mailing details and payment options if taxes are owed. This careful approach will help avoid potential issues with the Illinois Department of Revenue.

Obtain Answers on Illinois 1120

What is the Illinois 1120 Form?

The Illinois 1120 Form is a tax return used by corporations to report income and calculate the replacement tax owed to the state of Illinois. It is specifically for tax years ending on or after December 31, 2020, and before December 31, 2021. Corporations must complete this form to comply with Illinois tax regulations.
Who needs to file the Illinois 1120 Form?

Any corporation operating in Illinois, including those that are unitary filers or foreign insurers, must file the Illinois 1120 Form. Additionally, if a corporation is making a business income election to treat all nonbusiness income as business income, it also needs to complete this form.
When is the Illinois 1120 Form due?

The due date for filing the Illinois 1120 Form typically aligns with the federal tax return due date for corporations. If the corporation operates on a fiscal year, the due date will be the 15th day of the 5th month after the end of the fiscal year. For specific due dates, refer to the instructions provided with the form.
What information is required to complete the Illinois 1120 Form?

To complete the Illinois 1120 Form, corporations must provide:
- Legal business name and mailing address
- Federal Employer Identification Number (FEIN)
- Accounting method (cash, accrual, or other)
- Income and loss figures, including details on deductions and credits
- Any applicable schedules, such as Schedule M or Schedule 1299-D
What happens if I fail to file the Illinois 1120 Form on time?

Failure to file the Illinois 1120 Form by the due date may result in penalties and interest on any unpaid taxes. The Illinois Department of Revenue can impose additional fees for late submissions. It is important to file on time to avoid these financial consequences.
How can I make a payment for the taxes owed on the Illinois 1120 Form?

If there is a tax liability, payments can be made electronically at Tax.Illinois.gov. Alternatively, corporations may mail their payment along with Form IL-1120-V, a payment voucher. The check or money order should be made payable to the "Illinois Department of Revenue" and include the FEIN and tax year ending on the memo line.

Common mistakes

Filling out the Illinois 1120 form can be a daunting task, and many make mistakes that could lead to delays or penalties. One common mistake is failing to check the appropriate boxes in Step 1. This section requires you to indicate whether this is your first return or if there have been any changes to your business name or address. Neglecting to do this can cause confusion and may result in processing issues.

Another frequent error occurs when entering financial figures. Some individuals mistakenly enter negative numbers where only positive amounts are allowed. For example, the net operating loss deduction cannot be negative. This error can lead to incorrect calculations and ultimately affect your tax liability. Always double-check your entries to ensure they align with the instructions provided.

In addition, many overlook the importance of attaching necessary documents. If you are required to include federal forms or schedules, failing to attach them can result in the disallowance of deductions or credits. It is crucial to read through the instructions carefully and ensure all required documents are submitted with your return.

Finally, one of the most significant mistakes is not signing the form. Under penalties of perjury, you must declare that the information provided is true and complete. A missing signature can delay the processing of your return and may lead to penalties. Make sure to review your form thoroughly and sign it before submission.

Documents used along the form

The Illinois 1120 form is a crucial document for corporations operating in the state, but it often requires additional forms and documents to be filed alongside it. Each of these documents serves a specific purpose and ensures that all relevant financial information is accurately reported to the Illinois Department of Revenue. Below is a list of commonly used forms that complement the Illinois 1120.

U.S. Form 1120: This is the federal income tax return for corporations. A copy must be attached to the Illinois 1120 to provide a complete picture of the corporation's income and expenses.
Schedule UB: Used by unitary filers, this schedule details the income and deductions of a combined group of corporations that are related through ownership.
Schedule INS: This form is required for foreign insurers to report their income and expenses accurately while filing their Illinois taxes.
Form IL-4562: This document is used to report special depreciation additions and subtractions, which can impact the overall tax liability.
Schedule 80/20: This schedule addresses related-party expenses, allowing corporations to report additions and subtractions related to transactions with affiliated entities.
Schedule K-1-P or K-1-T: These forms report the distributive share of income, deductions, and credits from partnerships and S corporations, which must be included in the Illinois return.
Schedule NB: This schedule is for reporting nonbusiness income or loss, which is essential for determining the corporation's taxable income in Illinois.
Schedule 1299-B: This form is used to report various subtractions related to dividends and interest from specific business activities, such as high-impact businesses and contributions.
Schedule INS or UB/INS: These schedules are for foreign insurers and unitary filers to report reductions in income tax and replacement tax.
Form IL-2220: This form is used to calculate any penalties for underpayment of estimated tax, ensuring that the corporation remains compliant with state tax laws.

Filing the Illinois 1120 form accurately requires careful attention to detail, including the proper completion of accompanying documents. Each form plays a vital role in ensuring compliance and avoiding potential penalties. It is essential for corporations to understand the requirements and gather all necessary paperwork before submission.

Similar forms

Form 1120 (U.S. Corporation Income Tax Return): This federal form is similar to the Illinois 1120 as both are used by corporations to report income, deductions, and tax liability. Both forms require detailed financial information and follow similar reporting periods.
Form 1120-S (U.S. Income Tax Return for an S Corporation): Like the Illinois 1120, this form is for corporations but specifically for S corporations. Both forms require the reporting of income and deductions, but the tax treatment differs due to the S corporation's pass-through taxation.
Form 1065 (U.S. Return of Partnership Income): While this form is for partnerships, it shares similarities in that it reports income and deductions. Both forms require detailed financial disclosures, although the ownership structure and tax implications differ.
Form IL-1040 (Individual Income Tax Return): This state form is used by individuals to report personal income. Both forms require income reporting, but the IL-1120 is for corporations, while the IL-1040 is for individuals.
Form 990 (Return of Organization Exempt from Income Tax): Nonprofits use this form to report their financial activities. Both the 990 and IL-1120 require transparency in financial reporting, but the 990 focuses on exempt organizations.
Form 941 (Employer's Quarterly Federal Tax Return): This form is used to report payroll taxes. Both forms require accurate financial reporting, but the 941 focuses on employment taxes, while the IL-1120 focuses on corporate income.
Schedule C (Profit or Loss from Business): Used by sole proprietors, this form reports business income and expenses. Both forms aim to determine taxable income, but the IL-1120 is for corporations, while Schedule C is for individuals.
Form 1065-B (Return of Income for Electing Large Partnerships): This form is for large partnerships and shares similarities in reporting income and deductions. Both forms require detailed financial information but apply to different entity types.
Form 1120-F (U.S. Income Tax Return of a Foreign Corporation): Foreign corporations use this form to report U.S. income. Both forms require income reporting, but the IL-1120 applies to Illinois corporations, while the 1120-F is for foreign entities.
Form IL-990-T (Exempt Organization Income Tax Return): This form is for exempt organizations to report unrelated business income. Both forms require financial reporting, but the IL-990-T is specifically for tax-exempt entities.

Dos and Don'ts

When filling out the Illinois 1120 form, it is crucial to follow specific guidelines to ensure accuracy and compliance. Here are four essential dos and don'ts to keep in mind:

Do enter your complete legal business name accurately. This is vital for proper identification.
Do check all applicable boxes, especially for first or final returns. This helps the state process your return correctly.
Don't leave any required lines blank. Each section must be completed to avoid delays or penalties.
Don't forget to attach necessary supporting documents. Missing documents can lead to disallowance of deductions or credits.

Misconceptions

Only large corporations need to file the IL-1120 form. Many small businesses and corporations also need to file this form, depending on their income and business structure.
The IL-1120 is the same as the federal 1120 form. While they share similarities, the IL-1120 has specific requirements and calculations unique to Illinois tax laws.
You can file the IL-1120 anytime during the year. There are specific due dates for filing, and missing these deadlines can result in penalties.
All income is taxable in Illinois. Some types of income may be exempt or subject to different tax treatments, so it’s important to review what applies to your situation.
If I owe taxes, I can just pay later. It’s crucial to pay any taxes owed by the due date to avoid interest and penalties.
Filing the IL-1120 is optional for corporations. If your corporation meets certain income thresholds, filing is mandatory.
You don’t need to keep records after filing. Maintaining accurate records is essential for future reference and potential audits.
Only profits are reported on the IL-1120. Losses can also be reported and may affect future tax liabilities.
Once filed, the IL-1120 cannot be amended. You can amend your return if you discover an error or need to make changes.

Key takeaways

Filling out the Illinois 1120 form is an essential task for corporations operating in the state. Understanding the key aspects of this form can help ensure compliance and accuracy. Here are ten important takeaways:

Tax Year Specification: The form is specifically for tax years ending on or after December 31, 2020, and before December 31, 2021.
Due Dates: Be aware of the due dates for filing the form. Refer to the instructions for specific deadlines.
Complete Business Information: Provide the full legal name and mailing address of your corporation. Indicate any changes if applicable.
First or Final Return: Check the appropriate box if this is your first or final return. Include termination dates if applicable.
Attachments Required: Ensure to attach necessary federal forms and schedules as indicated in the instructions. Missing documents may lead to penalties.
Income Calculation: Accurately report your federal taxable income and any deductions or additions as required in the form.
Apportionment: If your business operates in multiple states, complete the apportionment section to determine the income allocable to Illinois.
Net Income Calculation: Follow the steps to calculate your net income, considering all relevant taxes and deductions.
Payment Instructions: If you owe taxes, include your payment with the form. Use the provided voucher for mailing payments.
Signature Requirement: The form must be signed by an authorized officer. This verifies the accuracy of the information provided.