1-A: Idaho Worksheet 1-A (Revision)
Idaho · Idaho Tax Commission · Used for tax years 2024, 2025, 2026
Idaho Worksheet 1-A calculates the Idaho-apportioned amounts of federal deductions for tips, overtime, car loan interest, and seniors. It adds those amounts and any QBI worksheet total for entry on Form 43, line 40. The supplied worksheet is labeled 2025, not 2024.
What you'll need
The worksheet directs you to use your federal Schedule 1-A. It also references these forms and amounts:
- Federal Schedule 1-A: Lines 6 and 13 for tips, lines 14c and 21 for overtime, line 30 for car loan interest, and line 37 for the senior deduction.
- Idaho amounts: The Idaho amounts included in federal Schedule 1-A, lines 6 and 14c.
- Idaho Form 43: Line 20, Idaho Total Income.
- Federal Form 1040: Line 9, Federal Total Income.
- QBI worksheet on page 21: The total, if any.
Common mistakes
- Do not use an apportionment percentage above 100%. The worksheet states this limit for lines 2, 5, 10, and 15.
- Use your federal Schedule 1-A to complete the worksheet. This reminder is printed on the form.
Questions people ask
How do I calculate the Idaho tips deduction?
Enter the federal Schedule 1-A, line 13 amount in column a, the line 6 amount in column b, and the Idaho amount included in line 6 in column c. Divide column a by column b to get the percentage on worksheet line 2, limited to 100%. Multiply that percentage by column c and enter the result on line 3.
How do I calculate the Idaho overtime deduction?
Enter the federal Schedule 1-A, line 21 amount in column a, the line 14c amount in column b, and the Idaho amount included in line 14c in column c. Divide column a by column b to get the percentage on worksheet line 5, limited to 100%. Multiply that percentage by column c and enter the result on line 6.
How are car loan interest and the senior deduction apportioned to Idaho?
For both parts, divide Idaho Total Income from Form 43, line 20, by Federal Total Income from Form 1040, line 9. The percentage cannot exceed 100%. For car loan interest, multiply that percentage by federal Schedule 1-A, line 30, and enter the result on worksheet line 11. For the senior deduction, multiply the percentage by federal Schedule 1-A, line 37, and enter the result on worksheet line 16.
Where does the total deduction go?
Add worksheet lines 3, 6, 11, and 16 and enter the result on line 17. Enter the total from the QBI worksheet on page 21, if any, on line 18. Add lines 17 and 18, then enter the total on worksheet line 19 and Form 43, line 40.