Illinois Schedule 1299-DA – Credit for Tax Paid to Other States – Detail (2026)

Last reviewed: 2025-11-07

Use the Illinois Tax Form Calculator Schedule 1299-DA: Credit for Tax Paid to Other States – Detail as a stand alone tax form calculator to quickly calculate specific amounts for your 2026 Illinois state tax return. Alternatively, you can use one of our Combined Federal and State Tax Estimators to quickly calculate your salary, tax, and take-home pay.

Schedule 1299-DA provides the detailed calculation for the Credit for Tax Paid to Other States. It supplements Schedule CR by listing each state, the income subject to both states’ tax, and the corresponding credit. This ensures Illinois residents and part-year residents avoid double taxation when earning income in another state.

When to File Schedule 1299-DA

Attach Schedule 1299-DA if you earned wages or business income in another state and paid tax there. Illinois grants a credit up to the lesser of the tax paid to the other state or the Illinois tax on the same income. You must complete a separate Schedule 1299-DA for each state where tax was paid.

Steps to Calculate the Credit

1. Enter the name of the state where you paid tax.
2. List the portion of your income taxed by both Illinois and that state (Line 2).
3. Multiply by the Illinois flat rate of 4.95%. This is the Illinois tax on that income (Line 3).
4. Enter the amount of tax actually paid to the other state (Line 4).
5. The allowable credit (Line 5) is the lesser of Lines 3 or 4.
6. Total all credits from all states (Line 6) and transfer to Schedule CR.

Attach proof of payment such as W-2s, 1099s, or the other state’s return. Without documentation, credits may be disallowed.

Example

Example: A resident of Illinois works part of the year in Indiana, earning $50,000. Indiana tax on that income is $1,800. Illinois tax on the same income is $2,475 (4.95%). The credit allowed is the lesser — $1,800. The taxpayer lists Indiana on Schedule 1299-DA and transfers $1,800 to Schedule CR.

How Schedule 1299-DA Differs from Schedule CR

Schedule CR summarizes the total credit amount, while Schedule 1299-DA provides the underlying detail for each state. This helps the Illinois Department of Revenue verify that all credits are properly supported and prevents overclaiming. If you have income from more than one state, complete multiple 1299-DA forms and total them on Schedule CR.

Tips for Compliance

• File the other state’s return before claiming credit on your Illinois return.
• Only include state-level income tax (not city, county, or school district taxes).
• Ensure the income listed matches both returns to avoid mismatch notices.
• Attach all supporting tax documents, especially W-2s showing out-of-state withholding.

Why This Credit Matters

Interstate workers and business owners can easily face double taxation if they do not claim this credit. Schedule 1299-DA formalizes the process, ensuring residents pay tax to only one state on the same income, in accordance with Illinois law and reciprocity agreements. It’s essential for maintaining fair and accurate multi-state tax compliance.

Related Forms and Resources

• Schedule CR – Credit for Tax Paid to Other States
• Form IL-1040 – Individual Income Tax Return
• Schedule NR – Nonresident and Part-Year Resident
• Illinois DOR – Credit for Tax Paid to Other States

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Important Notes

All calculations are estimates for guidance only. Always review your return and consider professional advice when submitting official filings.