Form 8829: Home Office Deduction Form Guide

Form 8829, Expenses for Business Use of Your Home, is the IRS form self-employed people use to calculate the home office deduction under the regular method. It works out what share of your home is used for business, applies that percentage to rent or mortgage interest, utilities, insurance and depreciation, limits the total to your business income, and sends the result to Schedule C. If you take the flat-rate simplified method instead, you skip Form 8829 entirely.

Our home office deduction guide explains whether you qualify. This post is the practical companion: how to fill out Form 8829 itself, part by part, with a worked example and the mistakes that cost people money years later when they sell. It is general information, not tax advice, so check specifics with a tax professional.

Who uses Form 8829

The IRS describes Form 8829 as the form used to figure allowable expenses for business use of your home on Schedule C and any carryover to the next year. You use it if all of these are true:

• You are a sole proprietor or single-member LLC filing Schedule C.
• Part of your home is used regularly and exclusively for business (or qualifies under the daycare or inventory storage exceptions).
• It is your principal place of business, or a place where you meet clients, or a separate structure used for business.
• You choose the regular method rather than the simplified method.

File a separate Form 8829 for each home you use for business. Employees, partners and farmers do not use the form.

Regular method vs simplified method

Feature	Regular method (Form 8829)	Simplified method
Calculation	Actual expenses x business-use %	$5 x square feet, max 300 sq ft
Maximum	No fixed cap (limited by business income)	$1,500
Depreciation	Yes, 39-year recovery	None (and none to recapture)
Mortgage interest and property tax	Business share on Form 8829	Full amount stays on Schedule A if you itemize
Carryover of unused amount	Yes	No
Paperwork	Higher	Minimal

You can switch methods from year to year. If you move from simplified back to regular, depreciation picks up using the tables for the remaining recovery period.

Form 8829 part by part

Part I: Part of your home used for business

You enter the square footage used regularly and exclusively for business and the total square footage of the home. The division gives your business-use percentage. Daycare providers who use space only part of the time also enter hours used to arrive at a time-space percentage, as explained in IRS Publication 587.

Part II: Figure your allowable deduction

Start with the gross income from the business use of your home, typically the tentative profit from Schedule C before the home office deduction. Then list expenses in two columns:

• Direct expenses benefit only the office, such as painting the office or repairing its window. They are deductible at 100%.
• Indirect expenses benefit the whole home, such as rent, mortgage interest, real estate taxes, homeowners insurance, utilities and general repairs. They are multiplied by the business-use percentage.

Expenses that only benefit the non-business part of the home, such as landscaping or a kitchen remodel, are not deductible at all.

The form then applies the income limit in order: mortgage interest, real estate taxes and casualty losses first; then operating expenses such as utilities, insurance and repairs; and finally depreciation. Anything that does not fit becomes a carryover.

Part III: Depreciation of your home

Homeowners enter the smaller of the home's adjusted basis or fair market value when first used for business, subtract the value of the land (land is never depreciable), and multiply the building's basis by the business-use percentage. The depreciation percentage comes from the 39-year nonresidential real property table, with a mid-month convention in the first year. For a full year, that works out to about 2.564% of the business basis.

Part IV: Carryover of unallowed expenses

Operating expenses and depreciation you could not deduct because of the income limit carry forward to the next year's Form 8829. Keep each year's form so the carryover is not lost.

Step by step: completing Form 8829

1. Measure the office and the whole home, and photograph the space to show exclusive use.
2. Gather annual totals: rent or mortgage interest statement (Form 1098), property tax bills, insurance, utilities and repair receipts.
3. Find your home's purchase price, cost of improvements and land value (from the property tax assessment or closing documents).
4. Calculate Schedule C tentative profit before the home office deduction.
5. Complete Parts I to IV, or let tax software do it from those inputs.
6. Carry the allowable amount to Schedule C line 30.

Worked example

Illustrative numbers. A freelance bookkeeper owns a 2,000 square foot home and uses a 240 square foot room exclusively as an office, so the business-use percentage is 12%. Her Schedule C tentative profit is $62,000.

Expense	Annual total	Business share (12%)
Mortgage interest	$14,000	$1,680
Real estate taxes	$5,000	$600
Homeowners insurance	$1,800	$216
Utilities	$3,600	$432
General repairs	$1,000	$120
Office repainting (direct)	$400	$400
Depreciation: building basis $300,000 x 12% x 2.564%		$923
Total		$4,371

The simplified method would give 240 x $5 = $1,200. The regular method produces a deduction more than three times larger, which also lowers her self-employment tax on Schedule SE. The trade-off is $923 a year of depreciation that may be taxed when she sells.

The remaining 88% of her mortgage interest and property taxes stays available on Schedule A if she itemizes. Under the 2025 tax law the state and local tax cap rose to $40,000 for 2025, rising 1% a year through 2029, with a phase-down at higher incomes, so the property-tax interaction is worth checking with software or a preparer.

Common Form 8829 mistakes

• Claiming a shared room. A dining table you also eat at fails the exclusive-use test.
• Including land in the depreciable basis. Only the building can be depreciated.
• Skipping depreciation to "avoid recapture." The IRS taxes depreciation that was allowable whether or not you claimed it.
• Losing carryovers. Without last year's Form 8829, unallowed expenses quietly disappear.
• Deducting 100% of the internet or phone bill here. Those business-use costs go on Schedule C directly, using a reasonable percentage.
• Using Form 8829 as an employee. W-2 remote workers cannot claim it.

Special cases: daycare, inventory storage and separate structures

The exclusive-use rule has two important exceptions. Licensed home daycare providers can deduct space used for daycare even if the family uses it at other times; instead of a pure square-footage percentage, they multiply it by the share of hours the space is available for daycare. A provider operating 55 hours a week uses 55 of 168 hours, about 32.7%, times the square-footage percentage. Sellers who store inventory or product samples at home can also deduct the storage area if the home is the only fixed location of the business and the space is used regularly for storage, even if not exclusively.

A detached studio, workshop or garage used regularly and exclusively for business qualifies without having to be the principal place of business. These structures are depreciated as nonresidential property too, and their expenses can be tracked directly rather than as a percentage of the whole home.

Audit-proofing your home office claim

Home office claims draw attention mainly when the facts are thin. Strengthen yours with a simple file:

• A floor plan or sketch with measurements of the office and the home.
• Dated photographs showing the space set up as an office and not used for other purposes.
• Evidence that it is your principal place of business: client meetings, invoices issued from the address, and a lack of another office.
• The utility bills, insurance declarations and mortgage statements behind each line.
• Copies of each year's Form 8829 to support carryovers and depreciation.

Keep these until at least three years after you file the return for the year you sell the home, since depreciation affects the sale.

Renters and Form 8829

Renters often get the best value from the regular method because rent is fully an indirect expense with no depreciation to recapture. A renter paying $2,400 a month with a 15% office would deduct $4,320 of rent alone, plus a share of renters insurance and utilities. Keep the lease and bank records showing rent paid.

What to do if you move or stop using the office

If you move during the year, file a separate Form 8829 for each home, using only the months each was used. If you stop using the office, depreciation stops, and any carryover generally cannot be used. When you sell the home, report depreciation recapture, a process our Form 4562 guide and depreciation calculation guide help you understand. A fixed asset register is a simple way to track the office basis year to year.

For more ways to cut your Schedule C profit legitimately, see our list of self-employed tax deductions. And because the home office limit depends on business income, accurate invoicing matters: create professional invoices with our free invoice generator, no sign-up required, and download each as a PDF for your records.