The home office deduction for landlords: the test that decides it

Ask whether a landlord can deduct a home office and every answer you find hedges. The hedge exists for a reason, but the reason is rarely named. Section 280A of the tax code allows the deduction only for space used in a trade or business, and a contractor filing Schedule C clears that bar automatically while a landlord filing Schedule E does not. The square footage, the $5 rate, the worksheet: all arithmetic. The trade or business question is the gate, and the only part genuinely in doubt.

So this guide will not tell you yes, because for some landlords the honest answer is no. It covers the test, what pushes a small portfolio over the line, the simplified-method math if you clear it, and the questions to put to your CPA, who makes the call on your facts.

The test: is your rental activity a trade or business

The tax code never defines “trade or business” in one tidy place, so this corner of it runs on case law. Owning assets and collecting the income is not enough; the Supreme Court long ago held that a man managing his own large investment portfolio full time was still an investor, not a business. What counts is regular, continuous activity carried on for income: advertising vacancies, signing leases, collecting rent, coordinating repairs. The operational work of running property, not the passive fact of holding it.

The case landlords cite is Curphey v. Commissioner, 73 T.C. 766 (1980). Dr. Curphey, a dermatologist with six rental units he managed himself, found tenants, prepared units between tenancies, and ran the paperwork from a home office. The Tax Court held his rental activity was a trade or business and allowed the deduction. There is no bright-line rule; the court weighed the nature and scope of what he actually did. Six self-managed units cleared the bar on those facts. One unit handed to a property manager, with your involvement limited to depositing a check, almost certainly would not.

What pushes the answer toward yes

The pattern in the cases is consistent. The stronger your file looks on these points, the more comfortable a CPA will be signing the return:

• You self-manage. You list the vacancies, screen the applicants, write the leases, schedule the plumber, and chase the late rent yourself. A property manager doing all of that weakens the claim; the business activity is happening at their office, not yours.
• The activity is regular and continuous. Something happens every month: rent tracking, a repair call, a renewal conversation, the books. Two bursts of effort a year around turnovers reads as investment upkeep, not operations.
• The scale is real. No magic unit count exists. Curphey had six; two or three self-managed units with genuine monthly work can present well, and ten units with none of the work done by you can still fail.
• Your records look like a business. A ledger per property, expenses sorted into Schedule E categories, leases and receipts you can produce on request. The habits in our guide to rental property accounting are the same habits that make the trade-or-business argument for you.

There is a useful rhyme with the QBI deduction's 250-hour safe harbor: different deduction, different test, but a contemporaneous log of rental-services hours is exactly the evidence that makes “regular and continuous” concrete here too. The deduction follows what you do, not what you own.

The space still has to pass its own test

Clearing trade or business gets you to the second gate, not through it. Section 280A also requires that the space be used regularly and exclusively for the activity, and that it be your principal place of business. Exclusively means exclusively. A guest room with a desk where the kids do homework fails. The space need not be a whole room; a clearly separated area used for nothing else can qualify.

The principal-place-of-business piece is friendlier than it sounds. Since 1999 the rule has included an administrative exception: if you use the space for the activity's administrative and management work (the books, the leases, the scheduling) and have no other fixed location where you do substantial administrative work, the office qualifies. Most self-managing landlords run the paperwork from home because there is nowhere else to run it from. The full rules, with examples, are in IRS Publication 587, Business Use of Your Home.

The simplified method, worked

If you pass both gates, the IRS offers a flat-rate option that skips the utility bills and the depreciation schedule entirely:

Deduction = square footage of the office (capped at 300) × $5, for a maximum of $1,500 a year.

Say your office is a 10 by 13 spare room, 130 square feet. That is 130 × $5 = $650. A 300 square foot converted garage hits the $1,500 ceiling. Two more rules ride along: the deduction cannot exceed the income from the activity after your other expenses, and under the simplified method any excess disappears rather than carrying forward. The trade is smaller paperwork for a smaller, cleaner number, and because the method claims no depreciation on your home, there is nothing to recapture when you sell the house. Your mortgage interest and property taxes stay fully on Schedule A as usual. The IRS describes the option on its simplified option page.

The regular method, and where the number actually goes

The regular method deducts the office's share of actual home costs. Say the 130 square foot office sits in a 1,625 square foot house: that is 8% of the home, so 8% of utilities, homeowner's insurance, and repairs that benefit the whole house, plus depreciation on 8% of the home's building basis over 39 years, the schedule for business-use space. On a $300,000 building basis the office share is $24,000, roughly $615 a year of depreciation. The total often beats $650, but every dollar of that depreciation is recaptured as taxable gain when you sell your home. Bigger number now, a bill at the exit.

Now the mechanical wrinkle. Form 8829, the home office form, attaches to Schedule C. It does not attach to Schedule E, and no Schedule E equivalent exists. In practice, preparers compute the allowable amount on a worksheet like the one in Publication 587 and report it among the expenses on Schedule E, typically as an other expense with a plain description. The math is the easy half; the placement is the preparer's judgment call.

A qualifying office changes your mileage

Here is the part that often outweighs the office itself. Drives between your home and a regular work location are commuting, not deductible. But if your home office is your principal place of business, the trip from home to the rental becomes a business drive, deductible at the 2026 standard rate of 72.5 cents per mile. Two visits a month to a property 7 miles away is 28 miles a month round trip, 336 miles a year, $243.60. Two such properties and the mileage alone is near $500. The two deductions stand or fall together; our mileage deduction guide covers the log you need to keep.

The questions to put to your CPA

This deduction is small enough in dollars and gray enough in law that the right move is to arrive prepared and let your preparer rule. Bring the square footage of the office and the home, a log of your hours and tasks, and a year of expenses already sorted by Schedule E category (a monthly close habit produces the third as a side effect). Then ask:

1. Given my unit count, my self-management, and my hours, does my rental activity rise to a trade or business in your judgment?
2. If it does, am I better off under the simplified method or the regular method on my numbers, counting the recapture cost at the end?
3. If we use the regular method, where will you report it on the return, and what documentation do you want me keeping for the percentage?
4. Does claiming the office change how we treat my mileage, and what does my log need to show?

I built rents.ai because my spreadsheets kept dropping exactly this kind of thread, and it handles the part of this page that is bookkeeping: every rental transaction sorted to its Schedule E line through the year, with a per-property rollup your CPA can read in one pass. It will not compute a home office deduction and it cannot judge whether your activity is a trade or business; that number stays a worksheet between you and your preparer. What it does is hand them a clean year so the only open question is the one this page is about.