Form 8829 - Expenses for Business Use of Your Home

What Form 8829 is

Form 8829, Expenses for Business Use of Your Home, is an IRS form used to work out the part of your home costs that relate to a business. It is filed only together with Schedule C (Form 1040), and the final figure on line 36 is carried to Schedule C, line 30. The current edition is the 2025 form, a single page with four parts: the business share of your home, the allowable deduction, depreciation, and the carryover of unallowed expenses to 2026.

Who typically needs it

Sole proprietors and single-member LLC owners who file Schedule C and use part of their home for business are the usual filers. The form asks for a separate Form 8829 for each home used for business during the year. Home daycare providers also use it, which is why lines 4 to 6 deal with hours of daycare use. The IRS instructions explain who qualifies and what counts as regular and exclusive use, so read them before you decide whether the form applies to you.

What you need before you start

• Your name and Social security number as they appear on your tax return.
• The square footage of the space used for business and the total square footage of the home.
• Your Schedule C, line 29 amount, plus any related gain or loss the instructions ask you to account for (line 8).
• Annual totals for mortgage interest, real estate taxes, insurance, rent, repairs, utilities and other home costs, split into direct and indirect expenses.
• If you claim depreciation: your home's adjusted basis or fair market value, and the value of the land.
• Any carryover amounts from your prior year Form 8829.

Keep the Instructions for Form 8829 open while you work. They explain each line and the columns on lines 9 to 22.

How to fill it out online with PDF Editify

Click "Fill Template Now" on this page. The form opens in the editor with its 58 fields ready to type into. Click a field, enter the value, and move to the next one. You can sign with a drawn, typed or uploaded signature in the editor and download the finished PDF once you have a plan.

Header

Enter the name of the proprietor and your social security number at the top of the page.

Part I: Part of your home used for business

• Line 1: area used regularly and exclusively for business, regularly for daycare, or for storing inventory or product samples.
• Line 2: total area of the home.
• Line 3: line 1 divided by line 2, entered as a percentage.
• Lines 4 to 6: only for daycare facilities not used exclusively for business. Multiply days by hours per day, use 8,760 hours on line 5 unless the instructions say otherwise, then divide line 4 by line 5.
• Line 7: the business percentage. Most filers copy line 3 here.

Part II: Figure your allowable deduction

Line 8 starts the calculation. Lines 9 to 11 (casualty losses, deductible mortgage interest, real estate taxes) and lines 16 to 22 (excess mortgage interest, excess real estate taxes, insurance, rent, repairs and maintenance, utilities, other expenses) each have a column (a) for direct expenses and a column (b) for indirect expenses. Direct expenses are for the business part of the home only, and indirect expenses are for the whole home. Lines 12 to 15, 23 to 24 and 26 to 36 are totals and comparisons based on the instructions. Line 25 is the carryover of prior year operating expenses, and line 31 is the carryover of prior year excess casualty losses and depreciation. Line 36 is the allowable expense that goes to Schedule C, line 30. If there is a casualty loss portion, line 35 sends it to Form 4684.

Part III: Depreciation of your home

Lines 37 to 42 cover the smaller of adjusted basis or fair market value, the land value, the building basis, the business basis, the depreciation percentage from the instructions, and the allowable depreciation, which you also enter on line 30.

Part IV: Carryover to 2026

Lines 43 and 44 show operating expenses and excess casualty losses and depreciation that were not allowed this year. Keep these amounts for next year's form.

Signing, and where and how to submit

Form 8829 has no signature line of its own. You sign your Form 1040, and Form 8829 travels with Schedule C as an attachment to that return. If you e-file, your tax software generates the form. If you file on paper, attach it behind Schedule C following the instructions for your return and the mailing address listed in the Form 1040 instructions. The official form page is irs.gov/forms-pubs/about-form-8829. If you need to put a signature on related paperwork, see how to sign a PDF. For an overview of other forms, see our guide to IRS tax forms.

Deadlines and fees

The IRS charges no fee for the form. Form 8829 is due with your income tax return, so it follows the due date of the Form 1040 it belongs to. The deadline for 2025 returns was April 15, 2026, or October 15, 2026 for those who filed an extension. For the following tax year, confirm the date in the Form 1040 instructions. Source: IRS, as of November 3, 2026.

Common mistakes

• Filing one Form 8829 for several homes instead of one per home.
• Mixing up column (a) direct and column (b) indirect expenses.
• Using a different square footage on line 1 than on a previous year without noting why.
• Forgetting the carryover amounts from last year on lines 25 and 31.
• Not carrying line 36 to Schedule C, line 30.
• Entering depreciation on line 42 but not on line 30.