A spreadsheet is a perfectly acceptable material participation log, and the regulations say so: participation can be established by any reasonable means. The reason owners move to an app is not that spreadsheets are disallowed. It is that a spreadsheet cannot prove when an entry was written, does not add up other people's hours against yours, and is easy to backfill in March — which is exactly the pattern courts distrust. Here is the comparison without the sales pitch.
What the log has to prove
Before comparing tools, be clear about the job. For the tests in Treas. Reg. §1.469-5T, a log needs to establish, for each property and each year:
- When the work happened (date, ideally time of day).
- What was done, specifically enough that a stranger could picture it.
- How long it took, in real minutes rather than round hours.
- Who did it — you, your spouse, a cleaner, a co-host — because the 100-hour test compares your hours to every other individual's.
- Why it should be believed — receipts, messages, photos that line up with the entries.
And for short-term rentals specifically, a second record: the number of stays and nights per property, so the seven-day average-stay test can be shown. Any tool that captures those things is adequate. The differences are in how easy it is to keep the record honest for twelve months.
Spreadsheet
Strengths. Free, flexible, familiar. You control the columns. A CPA can open it. The free log template gives you a layout that already has the fields above.
Weakness one: no creation timestamp. A spreadsheet shows the date you type into it, not the date you typed it. If an examiner asks whether the log was kept as the year went on or assembled the week before the return, the file itself cannot answer. Cloud version history helps a little, but it is fragile and few owners know how to produce it.
Weakness two: it is easy to backfill. That is the same feature seen from the other side. A blank month invites round numbers. Courts have rejected logs that were reconstructed from memory at filing time; see the guide on reconstructed versus contemporaneous logs. A spreadsheet does nothing to stop you from doing that, and nothing to prove you did not.
Practical friction. Nobody opens a spreadsheet in the driveway after a turnover. Entries get batched at the weekend, durations get estimated, and the record slowly becomes a summary.
Calendar apps
Strengths. Excellent timestamps. A calendar event created on the day it happened carries a creation time, and the app is already on your phone.
Weaknesses. No totals — you cannot see that you are at 62 hours on one property and 31 on another. No place for other participants' hours. No attachments in most calendars. And at year end, someone has to export events and turn them into a table a CPA can use. Owners who use a calendar usually end up keeping a spreadsheet as well, and reconciling the two.
A dedicated app
What to require before paying for one:
- Per-property logs with a running total against the test you chose (100-hour, 500-hour, or 750-hour).
- Entry creation timestamps stored separately from the activity date, so a backdated entry is visibly backdated.
- Other participants' hours recorded next to yours for the "more than anyone else" comparison.
- Attachments — a photo of the finished repair, the receipt — on the entry they support.
- Taxpayer and spouse kept separate but combinable, since the tests treat them differently.
- A stay counter for the seven-day average.
- A dated export per property and period that a CPA can open without an account.
What an app cannot do: it records what you enter. It does not pull your hours from Airbnb, it does not decide which hours count, and it does not make a weak year strong. If a product implies otherwise, be careful.
Side by side
| Spreadsheet | Calendar | Dedicated app | |
|---|---|---|---|
| Cost | Free | Free | Paid |
| Proof of when entered | Weak | Strong | Strong |
| Per-property totals vs test | Manual | None | Automatic |
| Other participants' hours | Manual column | None | Built in |
| Attachments on entries | No | Rarely | Yes |
| Spouse handling | Manual | Manual | Built in |
| Average-stay tracking | Manual | No | Built in |
| CPA-ready export | It is the file | Export then reformat | One report |
| Risk of backfilling | High | Low | Low |
Migrating an existing spreadsheet
If you have been keeping a spreadsheet, do not throw it away. Its entries are your history and its dates are your evidence, weak or not. Move it across so that everything lives in one place; STR Tracker imports a spreadsheet from the Files app on iOS, and entries you bring in keep their original activity dates while the import date is recorded separately. Mark the imported period as such in your notes. From that day forward, log live.
What your CPA would rather receive
Ask, and most will say: one file per property, sorted by date, with a total at the bottom, other participants' hours shown, and the supporting receipts in a folder that matches the entry dates. They do not want a calendar export, a photo roll, and a spreadsheet that disagree with each other. Whatever tool you choose, the test is whether it produces that package in ten minutes in February — see what to send your CPA for the full list.
The honest recommendation
If you own one property, do the turnovers yourself, and will genuinely open a spreadsheet the same day every time, a spreadsheet is fine. Most owners are not that person for twelve months in a row. The app's value is not sophistication; it is that logging from the phone in the driveway is the only version of "contemporaneous" that survives a busy season. You can try it free for 14 days and decide with your own log in front of you.