This guide is for Australian business owners, cross-border operators and international individuals with U.S. filing obligations. Use it for the U.S. side of your compliance. For Australian deductions, check current Australian Taxation Office (ATO) guidance separately.
We cover eligibility, regular versus simplified methods, each part of the form, deductible expenses, carryovers, records and filing points for 2026. Amounts are in US dollars and measurements in square feet, as the IRS uses them.
Key Takeaways
- Form 8829 calculates actual home office expenses; the simplified method skips the form.
- You need regular, exclusive business use plus a principal-place or client-meeting test.
- The form produces your business percentage, allowed expenses, depreciation and carryovers.
- A 2026 draft exists but is not for filing; the 2026 filing season uses the 2025 form.
What Is Form 8829 and Who Should Use It?
Form 8829, Expenses for Business Use of Your Home, is the U.S. IRS form that splits eligible home costs between business and personal use. It then calculates the deduction you can claim on a U.S. return.
The latest final version is the 2025 form. A 2026 draft form and instructions are marked "DRAFT - NOT FOR FILING."
Who can generally use Form 8829?
Sole proprietors reporting on Schedule C use it. A single-member LLC is disregarded unless it elects corporate treatment, so its activity decides the schedule, not the LLC label.
Other claimants take different routes:
- Partners with unreimbursed partnership expenses report on Schedule E, Part II, line 28, using the Publication 587 worksheet.
- Farmers report on Schedule F, line 32, also using the worksheet.
- Statutory employees follow the Schedule C line 30 rules.
What are the IRS home office eligibility tests?
The space must pass regular use (not occasional) and exclusive use (business only). A den used for legal work and family recreation fails. No permanent partition is required, but personal use generally disqualifies the area.
You must also meet one of these:
- Principal place of business: you regularly and exclusively handle administration or management there, with no other fixed location for that work. IRS example: a plumber who does all billing and records at home still qualifies.
- Client meetings: physical meetings must be substantial and integral. Occasional meetings or phone calls don't count.
- Separate structure: a freestanding studio, workshop or garage used exclusively and regularly for business.
Inventory storage and daycare have their own exceptions. Daycare can waive exclusive use if the business is licensed or exempt from licensing.
Who should not use Form 8829?
- W-2 employees. The unreimbursed employee home office deduction was suspended for 2018-2025. P.L. 119-21 makes that disallowance permanent from 2026.
- Simplified-method users for the same use.
- Partners and farmers, who use worksheets instead.
How does it connect to your return?
For Schedule C filers, Form 8829 line 36 flows to Schedule C line 30. Simplified-method filers use a worksheet that also feeds line 30.
Australian residents with no U.S. filing obligation should not use Form 8829 on an Australian return. The ATO runs a separate regime, including its fixed rate method for working from home. Keep the two systems apart.
Choose the Correct Home Office Deduction Method
Regular method
The regular method uses actual costs multiplied by your business percentage. It requires detailed records, home depreciation, income-limit checks and carryover tracking.
Simplified method
The simplified method is $5 per square foot, up to 300 square feet, for a maximum of $1,500. You report it on Schedule C line 30 without Form 8829. The eligibility tests still apply.
Side-by-side comparison
| Issue | Regular | Simplified |
|---|---|---|
| Calculation | Actual costs × business % | $5 × eligible sq ft (max 300) |
| Depreciation | Yes, on the home | None for the home |
| Carryover | Excess costs carry forward | No new carryover |
| Home sale | Depreciation may be recaptured | No recapture from simplified years |
| Records | Detailed | Area and use evidence |
Neither method is always better. You can switch each year, but the simplified election must be made on a timely filed original return.
What to gather first
- Business area and total home area, plus start dates
- Ownership or rental status, and rent or mortgage records
- Insurance, utilities, repairs and property taxes
- Home basis and land value
- Business income and prior-year carryovers
More than one home or business
- The simplified method applies to one home per year. Other qualifying homes use actual expenses, each with its own Form 8829.
- For partial years, average the monthly eligible area. A month counts only with 15+ qualifying days. A 400 sq ft space starting 20 July is capped at 300 sq ft and averages 125 sq ft.
- Use one method for all qualifying uses of the same home, and reasonably allocate the shared 300 sq ft cap.
Complete Form 8829: Part-by-Part Instructions
Part I: Part of your home used for business (lines 1-7)
Divide the business area by total home area to get your percentage, and record how you measured it. Daycare operators also factor in time use.
IRS example: Rene's daycare used 3,000 of 8,760 hours, or 34.25%. She applied that rate to direct basement costs and 17.12% to whole-home indirect costs.
Part II: Figure your allowable deduction (lines 8-36)
Line 8 generally starts from Schedule C line 29 (tentative profit), adjusted for relevant gains and losses. Operating expenses are limited by this income before excess casualty and depreciation.
Use two columns:
- Direct (column a): costs only for the office, such as painting that room.
- Indirect (column b): whole-home costs, apportioned by business percentage.
Expense categories include:
- Casualty losses, mortgage interest and real estate taxes
- Insurance (line 18) and rent (line 19)
- Repairs and maintenance (line 20)
- Utilities (line 21)
- Other eligible costs (line 22)
Line 35 removes the casualty portion for Form 4684 so it is not counted twice.
Part III: Depreciation of your home (lines 37-42)
Use the lesser of adjusted basis or fair market value when business use began, minus land, then multiply by your business percentage. For first use in 2025, the property is nonresidential real property under MACRS, depreciated over 39 years straight-line.
First-year percentages on line 41 run from 2.461% (January) down to 0.107% (December). Property first used after 12 May 1993 and before 2025 uses 2.564%.
Part IV: Carryover of unallowed expenses (lines 43-44)
When income limits block part of your deduction, the excess carries forward. Line 43 is operating expenses (line 26 minus 27). Line 44 is casualty and depreciation (line 32 minus 33). Neither goes below zero. Carryovers continue even if you leave the home, subject to limits.
Transfer the result
Line 36 goes to Schedule C line 30. Keep business and personal portions of shared costs separate so nothing is deducted twice.
Deductible Expenses, Limitations, and Recordkeeping
Which expenses may qualify?
These costs can qualify, depending on your facts and business use:
- Rent and mortgage interest
- Real estate taxes and insurance
- Utilities, repairs and maintenance
- Casualty losses and depreciation
Limitations that affect the calculation
- The gross-income limit caps operating expenses first.
- Direct costs are fully business; indirect costs use your percentage.
- Partial-year use and personal portions reduce the claim.
- Mortgage interest and property taxes may also appear as itemised deductions on Schedule A. Allocate them so the same dollars aren't claimed twice.
Records to keep
Publication 587 says to keep evidence of the business area, qualifying use, depreciation and expenses. Retain:
- Receipts, invoices, cancelled cheques and utility statements
- Rent, mortgage, insurance and property-tax records
- A floor plan or measurement worksheet, and photos
- Business-use dates, basis and improvement documents
- Depreciation calculations and prior-year Form 8829s
Retention is usually the later of 3 years from the return due or filing date, or 2 years after tax payment. IRS record guidance says to keep property records until the limitation period ends for the disposal year.
How to File Form 8829 in 2026 and Avoid Common Errors
Form 8829 is attached to your U.S. federal return with Schedule C. The IRS lists it in Free File Fillable Forms for the 2026 filing season (2025 tax year).
Key dates for tax year 2025:
- Most Form 1040 filers: 15 April 2026; Form 4868 extends filing, not payment, to 15 October 2026.
- U.S. citizens or residents living abroad: automatic extension to 15 June 2026, with interest running from the ordinary due date.
- Form 1040-NR with no U.S.-withheld wages: 15 June 2026.
Australian residents do not share one fixed U.S. filing date. Your return type and residency status set the deadline that applies.
Pre-submission checklist
- Correct tax year and current form revision
- Taxpayer and business details
- Business percentage and expense totals
- Income limit, depreciation and carryovers
- Reconciliation with Schedule C
Common errors
- Claiming a shared personal workspace
- Claiming the deduction just because you work from home
- Using Form 8829 and the simplified method for the same use
- Deducting mortgage interest or property taxes twice
- Ignoring prior-year carryovers
- Using unsupported depreciation figures
- Applying U.S. rules to an Australian return
Getting help
VJM Global is a Chartered Accountant firm with U.S.-compliant professionals and 30+ years of tax, audit and advisory experience. The firm helps Australian and other cross-border clients with supporting records, U.S. tax compliance coordination and home office deduction reviews.
This article is general information, not tax advice. Cross-border and entity-specific situations call for professional advice.
Frequently Asked Questions
What is Form 8829?
It is the IRS form eligible taxpayers use to calculate actual expenses for business use of a home. It is not an Australian tax form.
When can I use Form 8829?
Use it with the regular method when your home use qualifies and you report on Schedule C. Partners and farmers use worksheets instead.
How do I take a home office deduction?
Confirm you meet the use tests, then choose the regular or simplified method. Calculate the deduction and report it on Schedule C line 30.
How do I claim business use of home on taxes?
Allocate expenses between business and personal use, then report through Form 8829 or the simplified worksheet. Don't use both for the same space.
What qualifies as office expenses for taxes?
Direct expenses benefit only the office; indirect ones cover the whole home and are apportioned. Both need genuine business use and records.
How much is the standard deduction for a home office?
The IRS calls the simplified method a "standard deduction" of $5 per square foot, up to 300 square feet. It is separate from the personal standard deduction. Confirm current rates in IRS guidance.
