What is the principal place of business test?

What the publication says

Publication 587 begins by noting that you can have more than one business location, including your home, for a single trade or business. To qualify under this test, your home must be your principal place of business for that trade or business, and to decide that you must consider two things: the relative importance of the activities performed at each place where you conduct business, and the amount of time spent at each place.

The publication then supplies a simpler path. Your home office will qualify as your principal place of business if you meet two requirements. You use it exclusively and regularly for administrative or management activities of your trade or business, and you have no other fixed location where you conduct substantial administrative or management activities of your trade or business. If, after considering your business locations, your home cannot be identified as your principal place of business, you cannot deduct home office expenses under this test, although two other routes remain.

What counts as administrative or management work

The publication gives examples of activities that are administrative or managerial in nature: billing customers, clients or patients; keeping books and records; ordering supplies; setting up appointments; and forwarding orders or writing reports. The list says it is only a few examples, so similar back-office work counts too. The office does not need to be where the business earns its money. It needs to be where the paperwork of the business is done.

Things that do not disqualify you

The publication lists five situations that will not disqualify a home office from being your principal place of business. Others do your administrative work at locations other than your home, for example a billing company at its own premises. You do administrative work at places that are not fixed locations of your business, such as in a car or a hotel room. You occasionally do minimal administrative work at a fixed location outside your home. You do substantial nonadministrative work at a fixed location outside your home, such as meeting or serving customers there. And you have suitable space outside the home for administrative work but choose to use your home office instead.

Three examples from the publication

Sid is a self-employed plumber who spends most time at customers’ homes and offices and has a small home office used exclusively and regularly for administrative work such as phoning customers and doing billing. Sid has no other fixed location where this work is done, and the choice to have billing done by another company does not disqualify the office. Alex conducts administrative work at home and has no other fixed location for it; some work in a hotel room does not matter because a hotel room is not a fixed location. Taylor, an anesthesiologist, does administrative work at home and nowhere else fixed; doing substantial nonadministrative work at hospitals and choosing the home office over one the hospital offers also does not disqualify. In all three, the publication concludes the home office qualifies, subject to the usual limits.

Two other ways to qualify

Failing this test does not end the analysis. The first alternative is a place to meet patients, clients or customers: you physically meet them on your premises and their use of your home is substantial and integral to the conduct of your business, using the space exclusively and regularly. Doctors, dentists and attorneys with home offices generally meet this. Occasional meetings and phone calls do not. The second is a separate structure used exclusively and regularly for business, covered in can a detached garage be a home office? Neither requires the home to be the principal place of business.

Employees and multiple businesses

The publication’s Figure A flowchart asks whether you are using the part of your home as an employee, and answers that question with no deduction. The principal place of business test applies per trade or business. The publication says the same home office can be the principal place of business for two or more separate business activities, and each activity is determined separately, as long as you use the office exclusively and regularly for one or more of the permitted purposes.

When the test is passed, the next steps are the amount and the limit. See how to figure the percentage of your home used for business and the simplified vs regular home office deduction calculator. One more benefit the publication notes: if your home office qualifies as your principal place of business, you can deduct daily transportation costs between your home and another work location in the same trade or business (see Publication 463).

Sources

• IRS Publication 587, Business Use of Your Home (2025): Qualifying for a Deduction: Principal Place of Business. Read November 2, 2026.

Edition read: Publication 587 (2025), for use in preparing 2025 returns. Dollar figures and rates in the publication are for 2025; check IRS.gov/Pub587 and the instructions for Schedule C and Form 8829 for your tax year. This page summarizes the publication and does not replace it. Marked for human review.