Indiana — Corporate Income / Franchise Tax

Indiana imposes an adjusted gross income tax on corporations doing business in the state. The tax applies to that part of a corporation's adjusted gross income derived from sources within Indiana. C corporations are generally subject to the tax, while qualified S corporations are not subject to the adjusted gross income tax but must file annual information returns on Form IT-20S. Financial institutions defined as taxpayers under IC 6-5.5-1-17 are subject to a separate financial institutions tax and are exempt from the adjusted gross income tax.

For corporations with income from both within and outside Indiana, the state uses apportionment formulas to determine the Indiana-source income subject to tax. Effective for tax years beginning January 1, 2019, Indiana may impose the tax to the fullest extent permitted by the U.S. Constitution and federal law, regardless of whether the taxpayer has a physical presence in Indiana.

Source: Indiana Income Tax Information Bulletin #12

Indiana imposes a corporate adjusted gross income tax at a rate of 4.9% on the Indiana-source adjusted gross income of C corporations doing business in the state. This rate applies to taxable years beginning after June 30, 2021. The rate was phased down from 8.5% beginning in 2012, reaching 5.75% for taxable years beginning after June 30, 2018, 5.5% for those beginning after June 30, 2019, 5.25% for those beginning after June 30, 2020, and 4.9% for taxable years beginning after June 30, 2021.

Source: Ind. Code § 6-3-2-1

Effective January 1, 2019, Indiana imposes corporate adjusted gross income tax on income derived from Indiana sources "to the fullest extent permitted by the Constitution of the United States and federal law, regardless of whether the taxpayer has a physical presence in Indiana." A corporation has nexus if it derives any adjusted gross income from Indiana sources, which includes income from doing business in Indiana, income from tangible or real property located in Indiana, income from services rendered in Indiana, and income from intangible property sourced to Indiana under the statute's apportionment rules. Indiana does not impose a specific dollar threshold for corporate income tax nexus. Federal Public Law 86-272 protections continue to apply.

Source: Ind. Code § 6-3-2-2

Indiana uses a single-factor sales apportionment formula to determine the Indiana-source business income of multistate corporations. For taxable years beginning after December 31, 2010, the apportionment percentage is calculated by dividing the corporation's total receipts in Indiana by its total receipts everywhere. This single sales factor replaced the prior three-factor formula that included property and payroll factors. Nonbusiness income is allocated separately under different statutory rules.

Source: Ind. Code § 6-3-2-2(b) and Indiana Income Tax Information Bulletin #12

Indiana corporate adjusted gross income tax returns on Form IT-20 are due on the 15th day of the fifth month following the close of the taxable year. For calendar-year C corporations, this means the return is due May 15. This due date reflects federal changes enacted in 2015 that moved C corporation federal return due dates to the 15th day of the fourth month, and Indiana law provides that the state due date is one month after the federal due date for corporations whose federal return is due on or after the 15th day of the fourth month.

Source: Indiana Income Tax Information Bulletin #12

Effective for tax years beginning after December 31, 2018, Indiana adopted market-based sourcing for receipts from the provision of services and most intangible property transactions. Senate Enrolled Act 563-2019 enacted this change, which replaced the prior cost-of-performance sourcing method. Under market-based sourcing, service receipts are attributed to Indiana to the extent the taxpayer's market for the sale is in Indiana—meaning to the extent the benefit of the service is received in the state.

Statutory framework

Indiana Code § 6-3-2-2(m) provides that receipts, other than receipts from sales of tangible personal property, are in Indiana if and to the extent the taxpayer's market for the sales is in Indiana. The statute directs that a taxpayer's market for services is in Indiana to the extent that the purchaser of the service receives the benefit of the service in Indiana. For receipts from intangible property (other than sales of intangible property), the market is in Indiana to the extent the intangible property is used in Indiana.

Exceptions to market-based sourcing

Two categories of receipts remain subject to cost-of-performance sourcing rather than market-based sourcing:

• Telecommunications services as defined in Indiana Code § 6-2.5-1-30
• Broadcasting services as defined in Indiana Code § 6-3-2-2.6(d)

These receipts continue to be sourced under the income-producing-activity test based on where the greater proportion of the income-producing activity is performed, measured by costs of performance.

Hierarchical approach to determining benefit location

Indiana Department of Revenue regulation 45 IAC 3.1-1-55.5 implements the statutory market-based sourcing rules through a detailed, hierarchical framework. The regulation sets forth specific sourcing rules for different types of services and intangibles, with fallback provisions when the taxpayer lacks specific information about where the benefit is received.

General rule for services

The regulation distinguishes between services delivered to individual customers and services delivered to business customers:

Services delivered to individual customers by electronic transmission (45 IAC 3.1-1-55.5(s)) are sourced to Indiana if the customer receives the services in Indiana. In the absence of actual knowledge of the place of receipt, the taxpayer may source the receipts based on the customer's billing address.

Services delivered to business customers by electronic transmission (45 IAC 3.1-1-55.5(t)) are sourced to Indiana if and to the extent the employees or designees of the customer directly use the service in Indiana. If the taxpayer cannot determine where the service is used, the regulation provides a three-tier fallback hierarchy:

1. If the taxpayer knows where the contract is principally managed by the customer, source to that state
2. If the taxpayer cannot determine the principal management location, source to the state where the customer placed the order
3. If neither of the above can be determined, source to the customer's billing address

Services delivered to customers by physical means (45 IAC 3.1-1-55.5(r)) are attributed to the extent the customer receives the benefit in Indiana. For mail or parcel delivery services, the benefit is determined by the state to which the underlying item is delivered.

Professional services to individual customers (45 IAC 3.1-1-55.5(w)) are sourced to the customer's state of primary residence. If the taxpayer cannot reasonably identify the customer's state of primary residence, source to the customer's billing address.

Professional services to related parties (45 IAC 3.1-1-55.5(v)(6)) are sourced using a special rule: the portion of the taxpayer's services in Indiana must be in proportion to the related party's receipts from Indiana divided by the related party's receipts from all jurisdictions.

Reasonable approximation permitted

When a taxpayer does not have specific information regarding where the benefit of a service is received and cannot apply the regulation's prescribed fallback methods, the taxpayer may use any reasonable approximation method. The Department's guidance emphasizes that taxpayers should retain clear documentation supporting the use of any reasonable approximation sourcing method.

Effective date and retroactive application

The market-based sourcing statute enacted by Senate Enrolled Act 563-2019 applies to taxable years beginning after December 31, 2018. Indiana Department of Revenue regulation 45 IAC 3.1-1-55.5, finalized in 2024, provides that its provisions apply retroactively to January 1, 2019. For tax years beginning before January 1, 2019, receipts from services and most intangible property were sourced to Indiana if the greater portion of the income-producing activity was performed in Indiana, based on costs of performance.

Source: Ind. Code § 6-3-2-2(m) Source: 45 IAC 3.1-1-55.5 Source: Indiana Income Tax Information Bulletin #12

Indiana corporate adjusted gross income starts with federal taxable income as defined in Internal Revenue Code Section 63, then applies a series of Indiana-specific modifications. This "federal taxable income plus modifications" approach means that corporations generally begin their Indiana calculation with the bottom-line taxable income reported on federal Form 1120, line 30.

IRC conformity date

Indiana Code § 6-3-1-11 defines "Internal Revenue Code" as a fixed reference date, which the legislature updates periodically by statute. Indiana does not adopt a rolling conformity model. Senate Bill 243, signed into law on March 5, 2026, updated Indiana's IRC conformity date to January 1, 2026, for tax years beginning in 2026 and later. This update brings Indiana into general conformity with the federal One Big Beautiful Bill Act (OBBBA, Pub. L. 119-21, signed July 4, 2025), subject to specific Indiana decoupling provisions described below. For tax years beginning before 2026, Indiana conformed to the IRC as in effect on January 1, 2023.

Required additions to federal taxable income include:

• Charitable contributions deducted under IRC § 170
• State and local income taxes deducted under IRC § 63, except as otherwise provided
• Federal net operating loss deductions allowed under IRC § 172 (Indiana computes its own separate NOL)
• Bonus depreciation under IRC § 168(k)
• Special depreciation for qualified production property under IRC § 168(n), enacted by OBBBA (Indiana requires an addback to disallow this new federal deduction)
• IRC § 179 expense to the extent the federal deduction exceeds $25,000
• Interest on non-Indiana state and municipal obligations excluded under IRC § 103 but acquired after December 31, 2011
• Intangible expenses and related-party interest paid to affiliates or foreign corporations under IC 6-3-2-20, subject to specific statutory exceptions
• IRC § 250(a)(1)(B) deduction for net controlled foreign corporation tested income (formerly global intangible low-taxed income, or GILTI)

Required subtractions from federal taxable income include:

• Income exempt from taxation under the U.S. Constitution and federal statutes
• IRC § 78 gross-up for deemed-paid foreign tax credits
• Research and experimental (R&E) expenses that are deducted federally under IRC § 174 or under section 70302(f)(2) of the OBBBA, to the extent the taxpayer adds back those amounts because Indiana continues to allow immediate expensing of R&E costs charged to a capital account

The add-back for intangible expenses and related-party interest under IC 6-3-2-20 requires a corporation to add back royalties, interest, and other intangible payments to related entities unless the taxpayer meets one of nine statutory exceptions, including demonstrating that the transaction had a valid business purpose other than Indiana tax avoidance, was at arm's length, and that the recipient included the income in its own tax base subject to a comparable income tax.

Bonus depreciation allowed under IRC § 168(k) is neutralized for Indiana purposes. Taxpayers add back the full bonus depreciation amount in the year the property is placed in service and spread the deduction over the property's normal recovery period. Senate Bill 243 extended this treatment to the new IRC § 168(n) special depreciation allowance for qualified production property enacted in the OBBBA.

IRC § 179 expensing is capped at $25,000 for Indiana purposes. Corporations claiming the higher federal deduction must add back the excess in the year taken and may subtract it as depreciation over the property's life.

For corporations filing federal consolidated returns, Indiana generally requires separate company reporting unless the taxpayer qualifies for and elects combined reporting under IC 6-3-2-2(o)–(q) or files a separate Indiana consolidated return. The modifications apply at the entity level before apportionment.

Source: Ind. Code § 6-3-1-11 (IRC conformity date definition) Source: Ind. Code § 6-3-1-3.5 (modifications to federal taxable income) Source: Ind. Code § 6-3-2-20 (intangible expense addback) Source: Senate Bill 243, Fiscal Note (2026 conformity date update to January 1, 2026) Source: Indiana DOR 2026 Legislative Synopsis (IRC § 168(n) addback and other SB 243 provisions)

Indiana Code § 6-3-2-20 requires corporations to add back intangible expenses and directly related interest paid to affiliated group members or foreign corporations unless the taxpayer qualifies for one of nine statutory exceptions listed in subsection (c). Each exception requires specific disclosure on Schedule PIC filed with Form IT-20 and, at the Department's request, proof by a preponderance of the evidence.

The nine statutory exceptions are:

Exception (1) — The recipient is subject to tax under IC 6-3-2 (Indiana adjusted gross income tax) or IC 6-5.5 (Indiana financial institutions tax) and includes the corresponding item of income in its Indiana tax base.

Exception (2) — The recipient is subject to a tax imposed by another U.S. state or political subdivision that is substantially similar to the tax under IC 6-3-2, the recipient's income tax liability to that jurisdiction is not less than the recipient's income tax liability to Indiana, and the recipient includes the corresponding item of income in its tax base for that jurisdiction.

Exception (3) — The taxpayer makes a disclosure and can establish that: (a) the recipient is subject to an income tax treaty between the United States and a foreign country, (b) the recipient includes the corresponding item of income in its tax base subject to that treaty, (c) the recipient's income tax liability is not less than the recipient's income tax liability to Indiana, and (d) the transaction did not have Indiana tax avoidance as the principal purpose.

Exception (4) — The taxpayer makes a disclosure and can establish that: (a) the recipient regularly engages in transactions with unrelated parties on terms substantially similar to the subject transaction, and (b) the transaction did not have Indiana tax avoidance as the principal purpose.

Exception (5) — The taxpayer makes a disclosure and can establish that: (a) the payment was received from an unrelated party and, on behalf of that unrelated party, paid to the recipient in an arm's length transaction, and (b) the transaction did not have Indiana tax avoidance as the principal purpose.

Exception (6) — The taxpayer makes a disclosure and can establish that: (a) the recipient paid, accrued, or incurred a liability to an unrelated party during the taxable year for an equal or greater amount directly for, related to, or in connection with the same property giving rise to the expenses, and (b) the transaction did not have Indiana tax avoidance as the principal purpose.

Exception (7) — The taxpayer makes a disclosure and can establish that: (a) the intangible expense or directly related interest expense was paid, accrued, or incurred in connection with a transaction in which the taxpayer and the recipient deal with each other at arm's length under terms comparable to those that would apply with an unrelated party, and (b) the transaction did not have Indiana tax avoidance as the principal purpose.

Exception (8) — The intangible expense is not a directly related interest expense, and the taxpayer makes a disclosure and can establish that: (a) the intangible expense is paid at a commercially reasonable rate (arm's length standard under IRC § 482), (b) the recipient includes the corresponding item of income in its tax base subject to an income tax imposed by a U.S. state or political subdivision or by a country with which the United States has an income tax treaty, and (c) the recipient's income tax liability with respect to that item is not less than its income tax liability to Indiana.

Exception (9) — The taxpayer makes a disclosure and can establish that application of the add-back would subject the taxpayer or the recipient to a tax that is unconstitutional, beyond the authority of Indiana to impose, or otherwise unlawful.

Disclosure requirement and burden of proof

"Makes a disclosure" means the taxpayer provides with its IT-20 return on Schedule PIC: (a) the names, addresses, and federal employer identification numbers of the payor and recipient, (b) a description of the transaction and the intangible property involved, (c) the amount of the expense, (d) a copy of federal Form 851 (Affiliation Schedule), and (e) the information needed to determine the taxpayer's status under these exceptions. For exceptions (3) through (9), the taxpayer must be prepared to establish the exception's requirements by a preponderance of the evidence at the Department's request.

Tax avoidance principal purpose

A transaction is considered to have Indiana tax avoidance as the principal purpose if: (a) there is not one or more valid business purposes that independently sustain the transaction, and (b) the principal purpose of tax avoidance exceeds any other valid business purpose.

Commercially reasonable rate

For exception (8), a "commercially reasonable" rate means the rate meets arm's length standards under Treasury Regulation § 1.482-1(b) (the IRC § 482 transfer pricing standard). If the expense is determined not to be at a commercially reasonable rate or comparable arm's length terms, the required add-back is only the amount necessary to bring the expense to a commercially reasonable rate or arm's length terms.

Source: Ind. Code § 6-3-2-20

Indiana requires corporations subject to the adjusted gross income tax to make quarterly estimated tax payments when the annual tax liability after credits exceeds $2,500. Each quarterly payment must equal 25% of the corporation's estimated annual adjusted gross income tax liability for the taxable year, or alternatively, the corporation may use the annualized income installment method calculated under Internal Revenue Code Section 6655(e).

Due dates for calendar-year corporations

For corporations using a taxable year ending December 31, the four quarterly estimated tax returns and payments are due on or before:

• First quarter: April 20
• Second quarter: June 20
• Third quarter: September 20
• Fourth quarter: December 20

Due dates for fiscal-year corporations

For corporations using a taxable year that does not end on December 31, the quarterly due dates are the 20th day of the fourth, sixth, ninth, and twelfth months of the taxpayer's taxable year.

Calculation methods

Corporations may calculate each quarterly payment as the lesser of:

1. 25% of the corporation's estimated adjusted gross income tax liability for the current taxable year, or
2. The annualized income installment calculated under IRC § 6655(e) as applied to the corporation's Indiana adjusted gross income tax liability.

The annualized income installment method permits corporations with fluctuating income during the year to pay based on income earned to date rather than a flat 25% per quarter, with recapture of any reduction in later quarters as prescribed by IRC § 6655(e). A corporation may not use an annualized method that would not be allowable under federal IRC § 6655.

Safe harbor to avoid underpayment penalty

Indiana provides a current-year final liability safe harbor: no penalty is assessed on any quarterly payment that equals or exceeds 25% of the corporation's final adjusted gross income tax liability for the taxable year. This safe harbor operates retrospectively — even if a corporation underestimated its income when making quarterly payments, the penalty on any underpayment is assessed only on the difference between the actual amount paid and 25% of the corporation's final tax liability for the year.

Indiana statutes do not provide a prior-year safe harbor for corporations. Unlike the federal estimated tax regime under IRC § 6655, which allows large corporations to avoid penalty by paying 100% of the prior year's tax liability (subject to certain limitations), Indiana law measures safe harbor protection solely against the current year's final liability. A corporation that pays 25% of its prior year's tax in each quarter is not automatically protected from penalty if its current-year liability is higher; the safe harbor applies only when the payment equals or exceeds 25% of the current year's final liability.

Electronic payment requirement

If the Indiana Department of Revenue determines that a corporation's estimated quarterly adjusted gross income tax liability for the current year, or the average estimated quarterly liability for the preceding year, exceeds $5,000 (after application of any credits), the corporation must pay the estimated taxes by electronic funds transfer (as defined in IC 4-8.1-2-7) or by delivering in person or overnight by courier a payment by cashier's check, certified check, or money order to the Department. Corporations that pay by electronic funds transfer are not required to file an estimated tax return form, only to remit the payment. A payment required to be made by electronic funds transfer but not paid in that manner is subject to an additional penalty under IC 6-8.1-10-2.1(b)(5).

Penalty for underpayment

The Department assesses a penalty under IC 6-8.1-10-2.1(b) on corporations that fail to make required estimated payments. The penalty rate and calculation follow the general underpayment penalty provisions. However, the safe harbor described above limits penalty exposure to the difference between actual quarterly payments and 25% of the final current-year liability.

Transition to new statute for 2026

Indiana Code § 6-3-4-4.2, enacted by Public Law 205-2025, Section 11, governs estimated tax payments for taxable years beginning in 2026 and later. The new statute retains the $2,500 annual liability threshold, the 25% quarterly payment calculation, the same quarterly due dates, and the $5,000 electronic payment threshold. The core estimated-tax framework, including the safe harbor provisions, remains consistent across the transition.

Source: Ind. Code § 6-3-4-4.1 (estimated tax payments, applicable through 2025) Source: Ind. Code § 6-3-4-4.2 (estimated tax payments, effective for taxable years beginning in 2026)

Indiana is not a mandatory combined reporting state but permits corporations that are members of a unitary business to elect—or in some cases be required by the Department—to file combined returns. Combined reporting differs from Indiana's default separate-company approach and from the consolidated-return election; combined returns aggregate the business income and apportionment factors of unitary-group members to determine Indiana-source income.

Unitary business and eligibility

A combined return may include corporations that are part of a unitary business. The Indiana Department of Revenue determines whether a unitary business exists by evaluating factors such as centralized management, operational interdependence, functional integration, and economies of scale. Indiana follows the constitutional unitary-business principle established by the U.S. Supreme Court in Container Corp. of America v. Franchise Tax Board, 463 U.S. 159 (1983), and Allied-Signal, Inc. v. Director, Div. of Taxation, 504 U.S. 768 (1992). A unitary business relationship means maintaining business activities or operations that are of mutual benefit, dependent upon, or contributory to one another.

Petition requirement

A taxpayer seeking to file a combined return must petition the Indiana Department of Revenue for permission. The IT-20 Corporate Income Tax Booklet instructs taxpayers that the petition may be submitted through the DOR website at www.in.gov/dor/resources/legal/requesting-policy-guidance or mailed to the DOR Tax Policy Division. The petition must identify the members of the unitary group and provide each entity's federal employer identification number. The Department has discretion to grant or deny the petition.

Water's-edge vs. worldwide

Combined reporting in Indiana is limited to the "water's-edge" of the United States unless the taxpayer specifically requests and the DOR approves worldwide combined reporting. The IT-20 Booklet states: "combined reporting is limited to the 'water's-edge' of the United States unless specifically requested and approved otherwise."

Apportionment for combined groups: inclusion of all unitary members

Income Tax Information Bulletin #12 explains how Indiana apportions business income for combined groups. The Bulletin states: "the Indiana sales of all corporations within a unitary group will be taken into account in apportioning unitary business income to Indiana. This includes sales attributable to entities that are not subject to Indiana taxation under 15 USC Section 381 (P.L. 86-272)." After the combined business income is apportioned to Indiana using the combined group's receipts, "the total business income apportioned to Indiana will then be assigned among the individual corporations taxable in Indiana. Each taxable corporation is assigned a share of the business income according" to its relative contribution. The Bulletin notes that "this decision only applies to corporations who file combined tax returns in Indiana and does not apply to corporations filing consolidated returns in Indiana."

This approach—counting in the numerator the Indiana receipts of all unitary-group members, including those with no Indiana filing obligation due to P.L. 86-272 protection—is sometimes called the "Finnigan" method by tax practitioners. Indiana's guidance does not use that label, but the substantive rule is set out in Bulletin #12.

Continuation requirement and deadline to discontinue

Once the DOR grants permission to file on a combined basis, the taxpayer must continue to file combined returns until the DOR grants permission to use an alternative filing method. The IT-20 Booklet cautions: "After permission has been granted to file on a combined basis, the taxpayer must continue to file returns on this basis until DOR grants permission to use an alternative method."

A taxpayer wishing to stop filing combined must petition the DOR for permission within 30 days after the end of the tax year for which the taxpayer seeks to file on a different basis. For a calendar-year taxpayer, the petition deadline is January 30 of the following year.

Material changes in circumstances

If material changes in the composition or structure of the unitary group occur after the initial petition has been granted, the taxpayer must notify the DOR by checking a box on the IT-20 return header and enclosing a statement describing the changes.

Required attachments and schedules

The IT-20 Booklet directs taxpayers filing a combined return to complete Form IT-20RECAP (Reconciliation of Federal Taxable Income) and to enclose a list of all corporations that are members of the unitary group, noting each entity's federal employer identification number. The return must reconcile the members' combined adjusted gross income and include an apportionment schedule reflecting the combined group's Indiana receipts.

Statutory cross-reference

Indiana Code § 6-3-2-2 governs apportionment and combined reporting for multistate businesses. Subsections (o) through (q) of IC 6-3-2-2 address combined reporting for unitary groups. The statute delegates significant procedural detail to the Department of Revenue, which publishes that guidance in the IT-20 Booklet and in Information Bulletin #12.

Source: Indiana IT-20 Corporate Income Tax Booklet, 2024 Source: Indiana Income Tax Information Bulletin #12

Indiana automatically grants corporations filing Form IT-20 an extension to file if they have received or filed for a federal extension. The Indiana extension period is 30 days beyond the federal extended due date. For calendar-year C corporations, the federal extension moves the federal due date from the 15th day of the fourth month to the 15th day of the tenth month (October 15 for a December 31 year-end); Indiana then allows an additional 30 days to file, making the Indiana extended due date the 15th day of the eleventh month following the close of the taxable year.

Recognition of federal extensions

The IT-20 Corporate Income Tax Booklet states: "Indiana recognizes federal extensions of time to file." A corporation that has filed federal Form 7004 or received an approved federal extension automatically qualifies for the Indiana extension. The corporation must indicate on Form IT-20 that a valid federal extension has been granted by checking the appropriate box on the form. The corporation should enclose a copy of the federal extension form with the Indiana return when filed.

Indiana-only extension request

If a corporation does not have a federal extension but needs additional time to file its Indiana return, it must submit a written request to the Indiana Department of Revenue prior to the original due date of the return. The request should explain the reason the extension is needed. The IT-20 Booklet does not specify a particular form for such requests or provide detailed procedures for Indiana-only extensions beyond the written-request requirement.

Extension of time to file does not extend time to pay

The extension applies only to the filing deadline, not to the payment of tax due. The IT-20 Booklet states: "An extension of time to file does not extend the time to pay any tax due. Tax due must be paid by the original due date. Interest and penalty are calculated on late payments from the due date of the payment." Tax liability must be paid by the original due date—the 15th day of the fifth month following the close of the taxable year (May 15 for calendar-year corporations). Interest accrues on any unpaid tax from the original due date, regardless of whether the corporation has an extension to file.

90% payment threshold to avoid late-payment penalty

Indiana waives the late-payment penalty during the extension period if the corporation meets two conditions:

1. At least 90% of the total tax due for the taxable year is paid by the original due date, and
2. The remaining balance, plus interest accrued from the original due date, is paid in full by the extended due date.

If a corporation pays less than 90% of the tax due by the original due date, both penalty and interest will be charged on the unpaid balance from the original due date. Multiple third-party sources cite this 90% safe-harbor rule as an established Indiana practice for corporate income tax extensions, consistent with the state's treatment of individual income tax extensions under Information Bulletin #18, which provides: "An extension of time waives the late payment penalty if at least 90% of the tax due is paid by the original due date, and the remaining balance, plus interest, is paid in full by the extended due date."

The Indiana Department of Revenue has not published a corporation-specific information bulletin that explicitly sets forth the 90% payment threshold for Form IT-20 extensions as of the date of this section. Practitioners should confirm this threshold with the Department or rely on the parallel individual-income-tax guidance and longstanding industry practice.

Claiming extension payment on the return

When the corporation files its IT-20 return on extension, any payment made with or for the extension should be entered on the appropriate payment-credit line of the return. The form includes a line for "this year's extension payment" in the credits section. This amount will be credited against the corporation's total tax liability for the year.

Source: Indiana IT-20 Corporate Income Tax Booklet, 2024 Source: Indiana Income Tax Information Bulletin #18 (individual income tax extension guidance; corporate-specific bulletin not published)