IRS Form 8829 Instructions: Home Office Deduction Guide

What Is Form 8829 and How It Compares to the Simplified Method

When you run a business from home and file Schedule C, the IRS gives you two ways to calculate your home office deduction: the regular method (actual expenses) and the simplified method. Form 8829 is the one-page form required when you choose the regular method.

Under the regular method on Form 8829, you measure the exact percentage of your home used for business and apply that percentage to your actual housing costs. You also calculate a depreciation deduction for the business portion of the building if you own your home. The final allowable deduction from Form 8829, line 36 flows directly to Schedule C, line 30.

Under the simplified option, you do not file Form 8829. Instead, you multiply your allowable business square footage (capped at 300 square feet) by $5 per square foot on the Simplified Method Worksheet in your Schedule C instructions. You can switch between Form 8829 and the simplified method from year to year on a timely filed, original federal income tax return. Once you make the election for a tax year, it cannot be changed.

• IRS: Instructions for Form 8829 (2025)
• IRS: Simplified option for home office deduction

Who Needs to File Form 8829 (and Who Cannot Use It)

You file Form 8829 only if you report self-employment business income on Schedule C and elect to deduct actual expenses for the business use of your home. Form 8829 is filed as an attachment to Schedule C with your individual income tax return by your return due date. If you used more than one home for business during the year, you must file a separate Form 8829 for each home where you use the regular method. You can elect the simplified method for only one home per year. If you run multiple businesses from the same home, you allocate the line 36 deduction among your Schedules C using any reasonable method.

Before you can file Form 8829, your space must pass the qualifying tests in the 2025 Instructions for Form 8829. Generally, a specific room or separately identifiable space must be used exclusively and on a regular basis as your principal place of business, as a place where you physically meet patients, clients, or customers in the normal course of business, or as a separate unattached structure (such as a detached studio, garage, or workshop) used in connection with your trade or business.

Your home office qualifies as your principal place of business even if you perform your main service outside the home. To qualify, you must use the home space exclusively and regularly for administrative or management activities, such as billing clients, keeping books, ordering supplies, or setting appointments. You also must have no other fixed location where you conduct substantial administrative or management activities.

Two statutory exceptions allow you to use Form 8829 without meeting the exclusive-use test, while four groups of taxpayers are barred from using the form:

• Storage of inventory or product samples: You can deduct space used regularly (even if mixed with personal use) to store inventory or product samples if you sell products at retail or wholesale, keep the items in a separately identifiable space suitable for storage, and your home is the only fixed location of your trade or business.
• Licensed daycare facilities: You can deduct space used regularly for daycare for children, persons age 65 or older, or persons physically or mentally unable to care for themselves, even if your family uses the same space after hours. You must have applied for (and not been rejected), been granted, or be exempt from having a license, certification, registration, or approval under state law.
• Who cannot use Form 8829: W-2 employees (employee home office deductions are not allowed on personal returns), partners claiming unreimbursed partnership expenses, and farmers filing Schedule F. Partners and Schedule F filers claiming actual expenses must instead complete the Worksheet To Figure the Deduction for Business Use of Your Home and report the deduction on Schedule E or Schedule F, line 32.
• Inventory-only allocators and simplified filers: Do not file Form 8829 if all of your home business expenses are properly allocable to inventory costs (figure those in Schedule C, Part III instead) or if you elected the simplified method for that home.

• IRS: Instructions for Form 8829 (2025)
• IRS: Publication 587 (2025), Business Use of Your Home

Line-by-Line Walkthrough: Parts I Through IV

Form 8829 is divided into four parts that move from your floor plan measurements to your income limit, your building depreciation, and your carryovers to the next tax year.

• Part I: Part of Your Home Used for Business (Lines 1 to 7). Enter the area used regularly and exclusively for business (or regularly for qualified storage or daycare) on line 1, and the total area of your home on line 2. Divide line 1 by line 2 to get your business percentage on line 3. Unless you run a daycare facility in shared personal space, carry that percentage to line 7. Non-exclusive daycare providers use lines 4 through 6 to multiply their space percentage by the fraction of hours the space was used for daycare out of 8,760 total hours in a full year (prorated by multiplying 24 hours by the number of days available if you started or stopped daycare during the year).
• Part II: Figure Your Allowable Deduction (Lines 8 to 36). Line 8 sets your gross income limit from Schedule C, line 29 (adjusted for gains or losses on Form 8949, Schedule D, or Form 4797, or prorated if you also earn business income outside the home). Expenses are split into column (a) for Direct Expenses (100% for the business area, like painting the office) and column (b) for Indirect Expenses (for running the entire home, like utilities, insurance, and general repairs). Form 8829 deducts expenses in three priority tiers: Tier 1 (lines 9 to 14) takes casualty losses, mortgage interest, and real estate taxes. Tier 2 (lines 16 to 27) takes operating expenses like rent, utilities, insurance, repairs, and excess mortgage interest or real estate taxes up to your remaining profit on line 15. Tier 3 (lines 28 to 33) takes excess casualty losses and home depreciation up to whatever profit remains on line 28.
• Part III: Depreciation of Your Home (Lines 37 to 42). If you own your home, enter the smaller of your home's adjusted basis or fair market value on the date you first used it for business on line 37. Subtract the basis or value of the land on line 38 to get the building basis on line 39. Multiply line 39 by your business percentage (line 7) to find your business basis on line 40, then multiply by the IRS depreciation percentage on line 41 to get your allowable depreciation on line 42 (which also goes to line 30).
• Part IV: Carryover of Unallowed Expenses (Lines 43 and 44). Any operating expenses disallowed by the income cap are subtracted on line 43 (line 26 minus line 27), and any disallowed casualty losses and depreciation are subtracted on line 44 (line 32 minus line 33).

• IRS: Instructions for Form 8829 (2025)
• IRS: About Form 8829, Expenses for Business Use of Your Home

Standard Deduction vs. Itemizing (Lines 10, 11, 16, and 17)

Form 8829 requires different lines for mortgage interest and real estate taxes depending on whether you take the standard deduction or itemize on Schedule A.

If you claim the standard deduction, leave lines 10 and 11 blank. Instead, enter 100% of your qualifying home mortgage interest (for loans used to buy, build, or substantially improve the home) in column (b) of line 16, and enter 100% of the real estate taxes paid on the home in column (b) of line 17. If you are not increasing your standard deduction by a net qualified disaster loss, leave line 9 blank and enter business casualty losses on line 29.

If you itemize deductions on Schedule A, report deductible personal-limit mortgage interest in column (b) of line 10 and any excess mortgage interest in column (b) of line 16. For real estate taxes, the overall state and local tax (SALT) deduction limit is $40,000 ($20,000 if married filing separately). This limit is reduced when modified adjusted gross income exceeds $500,000 ($250,000 if married filing separately), but it is not reduced below $10,000 ($5,000 if married filing separately). If your total personal state and local income, sales, real estate, and personal property taxes are $10,000 or less ($5,000 if married filing separately), enter all real estate taxes on the home in column (b) of line 11. If they exceed $10,000, complete the Line 11 Worksheet in the instructions to split your business real estate taxes between column (a) of line 11 and column (a) of line 17.

• IRS: Instructions for Form 8829 (2025)
• IRS: Publication 587 (2025), Business Use of Your Home

Part III Depreciation Table and Rules (Line 41)

When you depreciate your home on Form 8829, the business portion is depreciated as nonresidential real property under the Modified Accelerated Cost Recovery System (MACRS) using the straight-line method over 39 years. You never depreciate the value of the land.

For homes first used for business after May 12, 1993, and before 2025, the standard annual depreciation percentage on line 41 is 2.564% (even if you used the simplified method in 2024 and switch to Form 8829 for 2025). If you first began using your home for business during 2025, your line 41 percentage depends on the month you started:

• IRS: Publication 587 (2025), Business Use of Your Home
• IRS: Instructions for Form 8829 (2025)

Worked Example: Completing Form 8829

Consider a worked calculation written by our team. Suppose you are a self-employed consultant filing Schedule C who takes the standard deduction on your individual return. You began using a 250-square-foot room exclusively and regularly as your principal place of business in 2023 inside your 2,000-square-foot home. All of your business gross income is earned from this home office, and your Schedule C, line 29 tentative profit is $4,000.

During 2025, you paid $400 to repaint the office (a direct expense), $10,000 in qualifying home mortgage interest, $4,000 in real estate taxes, $1,500 in homeowner's insurance, and $2,500 in utilities. When you started using the home for business in 2023, the home's adjusted basis (lower than fair market value) was $300,000, including $60,000 for the land.

• Part I (Business Percentage): Enter 250 on line 1 and 2,000 on line 2. Divide 250 by 2,000 to get 12.5% on line 3 and line 7.
• Part II, Tier 1 (Lines 8 to 15): Enter your $4,000 tentative profit on line 8. Because you claim the standard deduction, lines 9 through 14 are $0, leaving a deduction limit of $4,000 on line 15.
• Part II, Tier 2 (Operating Expenses, Lines 16 to 27): In column (a), enter $400 on line 20 and line 23(a). In column (b), enter $10,000 on line 16 (mortgage interest), $4,000 on line 17 (real estate taxes), $1,500 on line 18 (insurance), and $2,500 on line 21 (utilities), totaling $18,000 on line 23(b). Multiply $18,000 by 12.5% on line 24 to get $2,250. Add $400 and $2,250 to get $2,650 on line 26 and line 27 (since $2,650 is under the $4,000 limit).
• Part III (Home Depreciation, Lines 37 to 42): Enter $300,000 on line 37 and $60,000 for land on line 38, leaving a building basis of $240,000 on line 39. Multiply $240,000 by 12.5% to get $30,000 on line 40. Multiply $30,000 by 2.564% (line 41) to get $769 on line 42 and line 30.
• Part II, Tier 3 and Final Deduction (Lines 28 to 36): Subtract $2,650 from $4,000 to get a remaining limit of $1,350 on line 28. All $769 of depreciation is allowable on line 33. Add lines 27 ($2,650) and 33 ($769) to get $3,419 on line 34 and line 36, which flows to Schedule C, line 30 (beating the $1,250 simplified deduction for 250 square feet at $5 per square foot).
• Part IV (Carryover, Lines 43 and 44): Because all expenses fit under your $4,000 limit, lines 43 and 44 are $0. If your tentative profit had been $2,000, line 27 would be capped at $2,000, line 33 would be $0, and you would carry over $650 on line 43 and $769 on line 44 to 2026.

• IRS: Publication 587 (2025), Business Use of Your Home
• IRS: Simplified option for home office deduction

Recordkeeping Checklist and Home Sale Rules

You must keep records proving every figure on Form 8829 until the later of 3 years from the return due date or filing date, or 2 years after the tax was paid. Keep copies of prior Forms 8829 and improvement receipts for as long as you own the home. Use this checklist written by our team:

• Floor plan and measurement proof: Records showing the square footage (or room count if rooms are similar in size) of the business space and total home, proving exclusive and regular use.
• Operating expense receipts: Canceled checks, utility bills, insurance declarations, mortgage interest statements, property tax bills, lease agreements, and repair invoices.
• Depreciable basis documentation: Closing statements, original purchase price, property tax assessments splitting land and building value, and receipts for permanent improvements.
• Daycare and listed property logs: For home daycares, a log of operating hours and days available, plus a meal log if claiming 2025 standard meal rates ($1.66 breakfast, $3.15 lunch or dinner, and $0.93 snack in most states and territories). For listed property on Form 4562, a usage log proving more than 50% business use.
• Home sale and depreciation recapture note: If your office is inside your main home, you do not allocate gain between business and personal use when you sell. However, you must reduce your cost basis by the depreciation allowed or allowable on Form 8829 (even if you did not claim it), and you cannot exclude under the $250,000/$500,000 home sale exclusion the part of your gain equal to depreciation allowed or allowable after May 6, 1997.

• IRS: Publication 587 (2025), Business Use of Your Home
• IRS: Instructions for Form 8829 (2025)

Common Errors to Avoid on Form 8829

Watch out for these frequent errors highlighted in the IRS instructions:

• Putting the first landline telephone or general business costs on Form 8829: The basic local service charge (including taxes) for the first telephone landline into your home is a nondeductible personal expense. Business long-distance calls or a dedicated second line go on Schedule C, line 25, and supplies, wages, or advertising go on their own Schedule C lines.
• Claiming mortgage interest in column (a) as a direct expense: Never claim mortgage interest in column (a) on line 10, even for a separate structure, and never include interest on loans that did not benefit the home (like a home equity loan used for credit cards or a car).
• Depreciating the land on Part III: Always subtract the land value on line 38 before calculating your building basis on line 39.
• Double-counting depreciation on Schedule C, line 13: Attach Form 4562 only if you first used your home for business in 2025 or placed improvements in service in 2025. Never include the home depreciation from Form 8829, line 42 on Schedule C, line 13, because it is already included on Schedule C, line 30.
• Entering 8,760 hours for part-year daycare or full-year bills for part-year business use: Deduct only expenses incurred during the part of the year the home was used for business, and prorate part-year daycare hours on line 5 by multiplying 24 hours by the actual days available.
• Deducting a full remodeling job as a repair: Repairs done as part of an extensive remodeling or restoration that gives your property a new use (such as converting two rooms into a beauty salon) are permanent improvements that must be added to basis and depreciated over 39 years.

• IRS: Publication 587 (2025), Business Use of Your Home
• IRS: Instructions for Form 8829 (2025)

Filing Your Return with Aldro

Aldro is the cheapest way to get your business taxes done: $399 flat, with bookkeeping at $20 a month.

• IRS: About Form 8829, Expenses for Business Use of Your Home