Is claiming a home office going to get you audited? It is one of the most common questions we hear, and it often keeps business owners from taking a deduction they qualify for. Of all the tax strategies for business owners, this one is easy to leave on the table, especially if you also rent an office. The deduction is part of the tax law, and if you meet the rules and keep the records, you have no reason to avoid it.
Why a separate office does not rule you out
Many owners assume a rented office ends the conversation. It does not. According to IRS Publication 587 for 2025 returns, you can have more than one business location for the same business, and your home office can still be your principal place of business. Publication 587 is the IRS guide to the business use of your home, and the 2025 edition was the most recent as of October 29, 2026.
Picture a consultant who meets clients in a rented office but handles the billing and bookkeeping at home. Publication 587 says meeting clients at a fixed location outside your home does not, by itself, disqualify your home office. What matters is where the administrative and management work happens.
The three tests your home office has to pass
For the 2025 tax year, Publication 587 says a home office qualifies as your principal place of business through administrative work when all three of these are true:
- You use the space exclusively and regularly for business. Exclusive means only business, so a den the family also uses for movies fails.
- You use it for the administrative or management activities of your business, such as billing clients, keeping books and records, ordering supplies or setting appointments.
- You have no other fixed location where you do substantial administrative or management work for that business.
The space does not need a wall around it, but it has to be a specific, identifiable area. Occasional, minimal paperwork at your outside office does not disqualify you, and neither does working from a car or a hotel room. Having an outside desk available and choosing to do the work at home is also fine under Publication 587. The exclusive-use rule has two exceptions: space used regularly to store inventory or product samples when your home is the only fixed location of a retail or wholesale business, and certain daycare facilities.
These rules, as described here, are for sole proprietors and single-member LLC owners who report on Schedule C. Partners and S corporation owners follow different mechanics. W-2 employees generally cannot deduct unreimbursed work expenses on the federal return, per IRS Publication 529, except for a few listed categories.
The mileage rule many owners miss
Here is the part that often adds up to more than the office itself. Normally the drive from home to your office is commuting, and commuting is not deductible. But IRS Publication 463 says that if your home office qualifies as your principal place of business, you can deduct daily transportation between your home and another work location in the same business.
So the same 24-mile round trip to your rented office changes from personal commuting to business mileage. For 2026, the IRS standard mileage rate is 72.5 cents per mile from January 1 through June 30 and 76 cents per mile from July 1 through December 31. The rate for 2025 was 70 cents.
A worked example for 2026
Take a hypothetical Torrance consultant who files Schedule C, uses a 200-square-foot spare room only for business, and drives to a rented client office three days a week. The round trip is 24 miles, and they work 48 weeks in 2026, split evenly between the two halves of the year. They use the room regularly all year for billing, bookkeeping and scheduling, and do no substantial administrative or management work at another fixed location. Their business profit is well above the deductions below, and they use the standard mileage rate.
| Item (2026) | Calculation | Deduction |
|---|---|---|
| Home office, simplified method | 200 sq ft x $5 | $1,000 |
| Mileage, Jan 1 - Jun 30 | 1,728 miles x 72.5 cents | $1,252.80 |
| Mileage, Jul 1 - Dec 31 | 1,728 miles x 76 cents | $1,313.28 |
| Total | $3,566.08 |
Without a qualifying home office, those 3,456 miles would be commuting and worth nothing on the return. The simplified method uses $5 per square foot for up to 300 square feet, so it tops out at $1,500. You can instead deduct actual expenses on Form 8829, such as a share of rent or mortgage interest, utilities, insurance and depreciation, which takes more records but can produce a larger figure.
You choose a method each year and can switch, according to the IRS page on the simplified home office option. With the simplified method, your mortgage interest and real estate taxes stay personal expenses, deductible on Schedule A if you itemize.
An income limit applies either way. The simplified deduction cannot exceed the gross income from the business use of your home minus your other business expenses, so it cannot create a business loss, and any excess is not carried forward. Under the actual-expense method, the limit applies to operating expenses such as utilities and insurance and to depreciation, with separate rules for expenses like mortgage interest that are deductible anyway. Disallowed actual expenses can carry forward to a later year in which you use actual expenses.
Depreciation also matters when you sell. Under the actual-expense method, Publication 587 says you cannot exclude the part of your gain equal to depreciation allowed or allowable after May 6, 1997, even if you never claimed it. That part is generally taxed as unrecaptured section 1250 gain even when the rest is excluded. For years you use the simplified method, the IRS treats home depreciation as zero.
The records that back up your deduction
Publication 587 does not require a particular recordkeeping system, but your records must show which part of the home you use, that you use it exclusively and regularly for business, and the expenses and depreciation for that part. Keep receipts and canceled checks, plus records of your home's purchase price and improvements, which support depreciation and your gain when you sell.
For the car, Table 5-1 of Publication 463 calls for the date of each trip, the business destination, the business purpose, the miles for each business use and your total miles for the year. Publication 463 favors records made at or near the time of each trip, and a log updated weekly counts. You cannot deduct estimated amounts, and a log kept on your phone or computer counts as a written record. Photos of the office are not on the IRS list, but they are a simple way to show how the space looked and was used.
How California treats the home office deduction
If you file Schedule C, California generally starts from your federal business income. The 2025 Schedule CA (540) instructions say California adjustments to business income usually come from differences in depreciation methods and write-offs, so the depreciation piece of an actual-expense deduction may differ on your state return.
For employees, California did not adopt the federal suspension of miscellaneous itemized deductions. If you itemize on your California return, qualifying unreimbursed employee expenses may still be deductible there as miscellaneous itemized deductions, subject to a 2% floor and figured under California law, even though they no longer reduce federal tax for most employees.
Home office rules within your tax strategies for business owners
A properly supported home office deduction is a legitimate tax benefit. The IRS uses several methods to select returns for audit, including computer screening against norms for similar returns, so no deduction guarantees or rules out an audit. Audits are also less common than many people think, as our look at what the IRS data shows about audit odds explains. What supports your deduction is meeting the three tests and keeping the records that prove it.
Our team reviews the home office and the mileage that comes with it as part of our tax strategies for business owners, along with how your business is set up and how California treats it. If you work from home and also keep an outside office, Schedule a tax planning consultation and we will check whether your space qualifies.
