Form GT-103, titled the Indiana Gross Income Tax Return, is the primary state tax filing document that Indiana businesses use to report their gross receipts from various sources and calculate the appropriate Gross Income Tax liability based on the state’s progressive rate schedule. This form applies to corporations, partnerships, LLCs, and other entities conducting business in Indiana, requiring detailed reporting of Indiana-sourced income from sales, services, rentals, and other commercial activities. Unlike traditional income tax forms that focus on net profits, GT-103 captures gross receipts before deductions, making accurate classification of Indiana vs. non-Indiana revenue essential for compliance. Businesses must file monthly, quarterly, or annually depending on their gross receipts volume, with electronic filing mandatory for most taxpayers.
How To File Form GT-103
Indiana requires electronic filing for most GT-103 returns through INTIME (Indiana Taxpayer Information Management Engine) at intime.dor.in.gov. Paper filing is allowed only in limited circumstances. Filing frequency depends on your average monthly gross receipts:
- Monthly: Average ≥ $50,000
- Quarterly: Average $10,000 – $49,999
- Annual: Average < $10,000
Due dates: End of the month following the reporting period.
How To Complete Form GT-103 (Line-By-Line Instructions)
Header Information
- Indiana Account ID: Enter your 12-digit Indiana Taxpayer Identification Number.
- Federal EIN: Provide your nine-digit Federal Employer Identification Number.
- Business Name: Enter your legal business name as registered with Indiana DOR.
- Filing Frequency: Mark Monthly, Quarterly, or Annual.
- Tax Period: Specify the month/quarter/year covered (MM/YYYY or QX-YYYY).
- Due Date: Auto-calculates based on tax period.
Part 1: Gross Receipts
- Line 1: Total gross receipts from all sources worldwide.
- Line 2: Gross receipts sourced to Indiana (sales delivered in Indiana, services performed in Indiana).
- Line 3: Multiply Line 2 by your apportionment ratio (Indiana sales ÷ Total sales).
Part 2: Gross Income Tax Calculation
- Line 4: Deduct nontaxable gross receipts (exempt sales, interstate commerce).
- Line 5: Indiana taxable gross receipts (Line 3 minus Line 4).
- Line 6: Apply GT rate schedule:
- $0 – $1,000: 0.5%
- $1,001 – $3,000: 1.0%
- $3,001 – $15,000: 1.25%
- $15,001 – $50,000: 1.5%
- Over $50,000: 1.75%
Part 3: Supplemental Gross Income Tax (SGIT)
- Line 7: SGIT base (Line 5 minus certain deductions).
- Line 8: SGIT rate (3.15% for most businesses).
Part 4: Tax Due or Overpaid
- Line 9: Total tax (Line 6 + Line 8).
- Line 10: Credits and payments.
- Line 11: Balance due or refund.
Schedules (Required Attachments)
Schedule GT-103-ADJ: Adjustments to gross receipts (nontaxable items).
Schedule GT-103-AP: Apportionment worksheet.
Schedule GT-103-INC: Income source breakdown.
Electronic Filing Through INTIME
- Log into intime.dor.in.gov
- Select Gross Income Tax Return
- Choose GT-103
- Follow prompts to enter data
- E-pay any balance due
Key Compliance Tips
- File even if no tax is due
- Monthly filers must pay by the 20th
- Quarterly filers by last day of month following quarter
- Annual filers by April 15 (corporations) or April 30 (others)