How to prove short-term rental hours when the IRS asks

By Max Medvedev · 6 Aug 2026

Counting the hours is easy — proving them is the whole job

Hours are proven with a record kept as the work happens: each entry dated to the day, with start and stop times, the specific task described, and the hours of every other person who worked. The regulation accepts "any reasonable means." The Tax Court, in practice, accepts detail and rejects reconstruction.

Nearly every recent loss is an evidence failure, not a defeat on the rule. Mirch v. Commissioner, T.C. Memo 2025-128, is the demonstration: the court agreed the property met the seven-day average-stay test, and the owners still lost the entire deduction, because out of roughly 920 claimed hours the court found credible participation of under 100. The rule was never in doubt. The log was.

What a defensible entry actually contains

Six things, and the last is the one people skip:

1. The date the work happened — not the date it was written down.
2. Start and stop times, not a duration invented later.
3. The task described concretely enough to picture.
4. A length sized to that task — real entries land on odd numbers.
5. Who else worked, and for how long.
6. The record that corroborates it: message thread, invoice, receipt, photo.

Rows one, three and four are the Mirch record: a flat seven hours per turnover whether the stay ran 1 day or 14, twelve minutes to "read" and twelve to "send" every email, 744.5 hours of site management and on-call, and 168 cleaning hours contradicted by the professional-cleaner deduction.

Those six fields are the columns of our free log template — a spreadsheet with no email wall, where each column names the case that made it necessary.

Overclaiming fails the same way. In Penley, T.C. Memo 2017-65, roughly 2,520 hours were claimed — more than a full-time job's 2,000-hour year — with no start or stop times anywhere. The court found the total implausible and discarded the log rather than trimming it.

Real time beats reconstructed, and the courts say so plainly

Reg. §1.469-5T(f)(4) is the lenient half: participation may be shown "by any reasonable means," and daily time reports are "not required."

The strict half is the case law. Moss, 135 T.C. 365 (2010), supplies the sentence everyone quotes — the rules "do not allow a post-event ballpark guesstimate" — and holds that on-call time is not participation. Sezonov, T.C. Memo 2022-40, applied it to a short-term rental with no real-time log at all.

The wins share one shape. Windham, T.C. Memo 2017-68, paired a credible real-time record with outside corroboration, alongside a part-time job. Zarrinnegar, T.C. Memo 2017-34, was a full-time dentist who won on a log kept as the work happened. Birdsong, T.C. Memo 2018-148, met the "reasonable means" standard with detailed spreadsheets and credible testimony. Leyh, T.C. Summ. Op. 2015-27, goes furthest: a clean log earned the benefit of the doubt on hours left out of it. Credibility, once established, spends.

Round numbers and identical entries read as invention

A log where every turnover took 7 hours and every email 12 minutes describes a spreadsheet, not a year. Real work is lumpy. Hairston, T.C. Memo 2019-104, lost on padding — trivial one-hour entries, headings like "supervising painting," hours recorded weekly rather than daily. The padded entries tainted the ones that were real.

Hence the counterintuitive rule: quality beats quantity. Eight hundred defensible hours beat 1,200 inflated ones, because over-claiming invites a court to discard the whole record — as in Mirch and Penley.

The race is against one person, so both sides need a record

The workhorse test — Reg. §1.469-5T(a), test 3 — is more than 100 hours and more than any other single individual. Per person, never everyone combined. A complete file documents someone else's time as carefully as your own.

• Pohoski, T.C. Memo 1998-17, split across two condos: won where the owner showed he beat the manager's hours, lost where he could not.
• Barniskis, T.C. Memo 1999-258, had the seven-day average but investor-style bookkeeping hours that could not out-total a management company.
• Eger v. United States, 9th Cir. 2020, closed the clever exit: a management contract is not a lease, so the manager cannot be recast as your tenant.

Two margins run the other way. A spouse's hours count as the owner's under §469(h)(5), even with no ownership interest, and Padda, T.C. Memo 2020-154, shows the test-4 route: more than 100 hours in each of several activities aggregating past 500. The calendar does not bend, though — Gregg v. United States, 186 F. Supp. 2d 1123 (D. Or. 2000), held there is no proration in a short first year, so an October placed-in-service date still faces the full 100-hour bar.

What an examiner does before reading a single entry

The IRS Passive Activity Loss Audit Technique Guide has examiners establish the taxpayer's time across all activities in the initial interview — the day job, the commute — then ask whether the claimed hours are plausible against them. Distance comes next, then any manager whose work negates the owner's.

Three categories get struck however labeled. On-call and available time, per Mirch and Moss. Investor-type work — reviewing statements, studying reports, monitoring from a distance — under Reg. §1.469-5T(f)(2)(ii). And travel, which the guide says generally should not be considered and which sank Lucero, T.C. Memo 2020-136.

The eleven rules the cases leave behind

1. Real-time beats reconstructed.
2. Round numbers and identical durations are a red flag.
3. Actual work, with start and stop times, sized to the task.
4. On-call and available time is worthless.
5. Investor, bookkeeping, and passive-observation time does not count.
6. Where there is a manager, the manager's hours belong in the file too.
7. The other job's hours belong there too.
8. Corroboration wins: messages, invoices, receipts, photos, bank records.
9. Travel time is fragile.
10. Real estate professional status is not automatic material participation (Gragg, 9th Cir. 2016), and §280A personal use above the greater of 14 days or 10% of days rented at fair value caps deductions at rental income regardless of the log.
11. Quality over quantity.

What the failure costs, computed

An evidence failure, computed — an owner who logged plenty of hours, just not hours that count:

The on-call hours would have won the race outright. They never count — so the countable hours clear the 100-hour floor, still lose to the cleaner, and the loss stops at the passive gate instead of reaching the W-2.

Where your own year stands

Run your hours and reservation mix through the estimator — it applies all seven tests, names the highest other individual, and cites the rule behind every verdict.