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If you have been researching short-term rental tax strategy, you have seen it everywhere: “just put in 100 hours.” It sounds simple. It is also one of the most misunderstood rules in real estate investing, and it is where a lot of year-end buyers get tripped up.

The short answer

The 100-hour rule is one of seven IRS tests for material participation. Under it, you materially participate in an activity for the year if you spend more than 100 hours on it and your hours are not less than anyone else’s, including people who do not own any part of it. That second half is the part people skip.

For a short-term rental owner, meeting that test is one of the things that can turn rental losses from passive into non-passive, which is what allows them to offset other income. It is the heart of what people call the “STR loophole.” I explain the full strategy in my guide to material participation for Sedona STR owners. This article is the quick, plain-English version of the 100-hour test itself.

Two gates, not one

The 100-hour rule never works alone. A short-term rental has to pass two gates:

  1. The 7-day gate. Under the passive activity regulations, an activity is not treated as a “rental activity” if the average period of customer use is 7 days or less. You work that out by dividing your total rental days by the number of separate stays. Most Sedona STRs sit well under 7 days.
  2. The participation gate. Once the 7-day rule takes the activity out of the automatic-passive “rental” bucket, you still have to materially participate. The 100-hour test is the one most owners aim for.

Pass the first gate and miss the second, and your losses are generally still passive.

The part that catches people: everyone else’s hours

The rule says your hours cannot be less than any other individual’s. Your cleaner counts. Your handyman counts. A property manager and their staff count. So if you pass 100 hours but your cleaning crew logs 140 across the year, you did not meet this particular test, even though you worked hard.

That is why a full-service management company can quietly undo the strategy. If someone else is handling guest messaging, pricing, check-in coordination and repairs, their hours can easily exceed yours. Many owners who want to use this test run the guest-facing side themselves and hire out only cleaning and maintenance. Whether that works for you is a question for your CPA.

What counts, and what does not

The regulation draws a line between running the business and acting as an investor.

How do you prove your hours?

Here is a point most articles get wrong. The regulation does not require a daily time log. It says participation can be shown by any reasonable means, including reconstructing your time from calendars, appointment books and narrative summaries.

That said, a day-by-day log written at the time is much stronger evidence than reconstructing hours after the fact, and it is what I tell every buyer to keep. Date, task, minutes. A phone note works. Your guest message history, cleaner texts and receipts back it up. If you ever need to defend the hours, you will be glad you did it in real time.

The year-one trap: a short first year

The 100 hours are measured over the tax year. If you buy in January, you have twelve months. If you close in December, you do not. Here is what 100 hours looks like if you count only the days you own the property:

Closing dateDays left in 2026Hours per day to reach 100
December 131about 3.2
December 824about 4.2
December 1517about 5.9
December 221010
December 28425

The numbers get unrealistic fast. I ask year-end buyers to be honest with themselves about this before they write an offer. I walk through the full calendar in my year-end tax timeline for Sedona STR buyers.

Common mistakes

Where to go from here

The 100-hour test is only one piece. The bonus depreciation and cost segregation guides explain how the deductions themselves work, and the tax savings estimator gives you a range to take to your CPA. If you are thinking about a purchase and want to talk through how your own hours would work, book a 15-minute call.


Disclaimer: William Hamburg is an Associate Broker with Realty ONE Group Mountain Desert in Sedona, Arizona. He is not a CPA or tax attorney. This article summarizes general information from the federal passive activity regulations (Treasury Regulations sections 1.469-1T and 1.469-5T) as of its publication date and is not tax, legal or investment advice. How these rules apply depends on your individual facts, and rules can change. Confirm every item with your own CPA or tax advisor before making any purchase or filing decision.