No. Time spent available to guests, reachable by phone, or "on call" for a short-term rental does not count toward material participation. The Tax Court has said so twice in terms that leave little room: in Moss v. Commissioner (135 T.C. 365) the court held that on-call hours during which services were never actually performed do not count, and in Mirch v. Commissioner (T.C. Memo 2025-128) it gave zero hours to a block of eight hours per rented day described as being on call for guests. What counts is the time you spent doing something, and the record has to show each thing.
The claim hosts make
The argument is intuitive. A short-term rental runs around the clock. Guests arrive at midnight, locks fail on Sunday, the hot tub trips a breaker during dinner. A host who has to be ready for all of that feels, reasonably, that the whole stay is work. So the log says "guest stay, available 24/7," or assigns a standard number of hours to every night booked.
The regulations do not see it that way. Treas. Reg. §1.469-5T(f)(1) defines participation as work done by an individual in connection with the activity. Work is something performed. Readiness to perform it is not.
Moss: on call is not services performed
Moss involved a taxpayer with a full-time job at a power plant who owned rental properties and was trying to reach the 750 hours required for real estate professional status under §469(c)(7). His calendar and summary supported 645.5 hours of travel and work. To cover the gap, he argued that he was on call for the rentals during every hour he was not at the plant, and that those hours should count.
The court disagreed. The statute applies where the taxpayer "performs" more than 750 hours of services, and the regulations define personal services as work performed. While he was on call, the court said, he could have been called in to perform services, but those services were never actually performed. His on-call time did not satisfy any part of the requirement.
Moss was a 750-hour case, but the reasoning is about what a service is, and it applies equally to the 100-hour and other tests under §1.469-5T(a).
Mirch: eight hours per rental day
Mirch is the short-term rental version of the same point, decided in December 2025. The owner's log assigned eight hours of "site management" to each of 93 rented days, defined as being on call for guests, repairs, supplies, Wi-Fi, cable and snow removal, for 744.5 hours in total. The court counted none of it. Only actual time spent on the rental activity counts, it said, and the block was claimed simply because she was available if a guest needed her.
The court also acknowledged that she probably did perform some tasks during stays. The problem was that nothing in the record allowed it to estimate how many hours those tasks took. She would have needed close to an hour per rented day to reach 100, and the record did not support even that. The full case is covered in Mirch v. Commissioner: 944.5 STR Hours, Under 100 Counted.
What does count during a stay
Plenty happens during a stay that is genuine work. The task is to name it and time it:
- Answering a guest's message about parking, the thermostat or the checkout time.
- Walking a guest through a lockbox that will not open, by phone or in person.
- Driving over to reset a breaker, and the reset itself.
- Coordinating a plumber, meeting the plumber, checking the repair.
- Ordering a replacement for something the guest reported broken.
- Reviewing the security camera after a noise complaint and messaging the guest.
Each of those is an entry with a start, an end and a description. The evening you spent with your phone face-up on the table waiting for a message that never came is not.
The what counts as participation guide covers the categories in more detail, including the investor-activity carve-out that removes some management-review time as well.
Logging discrete responses instead of blocks
The habit that fixes this is logging at the moment the work ends. A guest calls at 10:40 p.m. about a beeping smoke detector; you talk them through replacing the battery and hang up at 10:58 p.m. That is an 18-minute entry, written at 10:59. STR Tracker's quick-add entry exists for exactly this: a few taps from the phone to record the task and the minutes while the details are still fresh, rather than a block reconstructed later.
Written that way, a busy stay produces several small, specific entries with obvious evidence behind them: the message thread, the call log, the order confirmation. Written as "on call, 8 hours," the same stay produces one entry that the court in Mirch gave nothing for.
Remote hosts and smart-lock check-ins
Self check-in does not create hours. Setting up the smart lock, writing the check-in instructions and generating a guest code are tasks with durations; the guest letting themselves in at 4 p.m. while you are elsewhere is not. Log the code you generated on Tuesday for the Friday arrival, with the minutes it took. Do not log Friday afternoon.
The same applies to noise sensors, camera alerts and automated messages. The time you spent configuring them counts once. The hours they run on your behalf do not.
Example: a five-night stay, honestly logged
| Date | Task | Duration |
|---|---|---|
| Thu | Generated lock code, sent check-in instructions | 0h 10m |
| Thu | Guest message: Wi-Fi password not working; reset router remotely, confirmed | 0h 20m |
| Sat | Guest reported dripping faucet; scheduled plumber, messaged guest with time | 0h 25m |
| Sun | Met plumber at property, checked repair, paid invoice | 1h 15m |
| Tue | Checkout inspection, restocked supplies, noted chipped counter for repair list | 1h 40m |
| Tue | Wrote guest review, replied to guest's review | 0h 15m |
Total for the stay: a little over four hours, every minute of which corresponds to something that happened and left a trace. Multiply that pattern across a year of stays and the 100-hour test is within reach for a hands-on owner without claiming a single hour of availability.
What to write down
For each interruption: what the guest needed, what you did, when it started and ended, and where the evidence is. For each setup task: the same. For the rest of the stay: nothing. A log with gaps between real entries is a credible log. A log with no gaps is the one that gets read as an estimate.