Updated October 18, 2026. Quick answer: Lines 10 to 12 of Form 1041 take the first three deductions: interest, taxes and fiduciary fees. The amounts come from the records of what the estate or trust paid or incurred during the tax year, and each line has items the instructions tell you to leave off.
What lines 10 to 12 ask for
The form words them as “Interest. Check if Form 4952 is attached”, taxes and “Fiduciary fees. If only a portion is deductible under section 67(e), see instructions”. The next deductions are on the deduction lines 13 and 14 page.
Line 10: interest
The instructions say to “Enter the amount of interest (subject to limitations) paid or incurred by the estate or trust on amounts borrowed by the estate or trust”, and that interest should be entered only if it “isn’t claimed elsewhere on the return.”
“Personal interest isn’t deductible.” Interest on a trade or business or rental activity “should be deducted on the appropriate line of Schedule C, E, or F (Form 1040)”.
Investment interest has its own form: “Use Form 4952, Investment Interest Expense Deduction, to figure the allowable investment interest deduction.” “If you must complete Form 4952, check the box on line 10 of Form 1041 and attach Form 4952.” Then “add the deductible investment interest to the other types of deductible interest and enter the total on line 10.”
Line 11: taxes
“Enter any deductible taxes paid or incurred during the tax year that aren’t deductible elsewhere on Form 1041.” The instructions list “State and local income taxes.” “State and local real property taxes.” and “State and local personal property taxes.”
They also warn: “The maximum deduction for state and local taxes is $40,000.” “Complete the State and Local Tax Deduction Worksheet, later, to see if your deduction is limited.”
Do not deduct: “Federal income taxes;” “Estate, inheritance, legacy, succession, and gift taxes;” “Federal duties and excise taxes;” or foreign real property taxes. Also: “You can’t deduct both.” That refers to state and local income taxes and general sales taxes.
Line 12: fiduciary fees
“Enter the deductible fees paid or incurred to the fiduciary for administering the estate or trust during the tax year.”
Fiduciary expenses include “probate court fees and costs, fiduciary bond premiums”, “the cost of certified copies of the decedent’s death certificate” and “costs related to fiduciary accounts.”
A tip: “Fiduciary fees deducted on Form 706 can’t be deducted on Form 1041.” See the Form 706 page.
Where the number comes from
Interest comes from lender statements for borrowing in the name of the estate or trust, taxes from the property tax bills and state payment records the fiduciary paid, and fiduciary fees from the fiduciary’s own statement of fees and court costs. The worksheet named on line 11 is in the instructions under the title State and Local Tax Deduction Worksheet, and this page does not reproduce it.
Where it goes next
All of the deductions are added on line 16, which the form words as “Add lines 10 through 15b”. Lines 13 and 14 are on the deduction lines 13 and 14 page and the rest of the deductions are on the lines 15a to 17 page.
Edition and line numbers
This page reads Form 1041 (2025) and the 2025 Instructions for Form 1041 and Schedules A, B, G, J, and K-1. Those are the current files irs.gov served on 2026-10-18, byte-identical to the archived copies. The form reads “For calendar year 2025 or fiscal year beginning” and the instructions carry the footer “Instructions for Form 1041 (2025)”. Check the year printed on your own Form 1041 and use the line numbers on that year’s form.
Common mistakes
- Deducting personal interest. The instructions say “Personal interest isn’t deductible.”
- Deducting estate or inheritance taxes on line 11. The instructions say not to deduct “Estate, inheritance, legacy, succession, and gift taxes;”
- Deducting the same fiduciary fees on both returns. The instructions say “Fiduciary fees deducted on Form 706 can’t be deducted on Form 1041.”
Related: Form 1041, Form 706, funeral costs and the estate, and state taxation of trust income.
Sources
- Instructions for Form 1041 and Schedules A, B, G, J, and K-1 (2025), U.S. Income Tax Return for Estates and Trusts: https://www.irs.gov/pub/irs-pdf/i1041.pdf
- Form 1041 (2025), U.S. Income Tax Return for Estates and Trusts: https://www.irs.gov/pub/irs-pdf/f1041.pdf
Read from the IRS documents linked above on October 18, 2026. General information, not tax advice. Your own facts decide the outcome, and a preparer, the account provider or the IRS is the right place to confirm anything consequential.