Renting your spare bedroom on Airbnb and renting your car on Turo are both taxable, but the rules come from different parts of the tax code. The day-count tests that govern a dwelling do not apply to a vehicle. Your car follows listed-property depreciation rules instead, and both activities live or die on your records.

Does the same day-count test apply to your car and your spare bedroom?

No. This is the single most misunderstood point in side-hustle rental taxes. IRC Section 280A, the vacation-home rule with its famous day-count test, applies to a dwelling unit: a house, apartment, condo, or similar property. A car is not a dwelling unit, so the 14-day and 15-day tests below govern your Airbnb, not your Turo. Your Turo vehicle is listed property under the depreciation rules, which use a different test entirely: whether more than 50% of its total use is qualified business use. Keep the two frameworks separate and the rest of this article falls into place. (IRS Publication 946, chapter 5.)

How do the Airbnb dwelling rules work?

Three buckets, determined by counting days.

First, if you rent the dwelling for fewer than 15 days in the year, the rental income is not taxable at all and you claim no rental deductions. The statute says it plainly: the income "shall not be included in the gross income of such taxpayer under section 61" (IRC Section 280A(g)). Publication 527 adds that this activity is not treated as a rental activity and does not go on Schedule E.

Second, if you rent for 15 days or more and your personal use stays within the limit, it is a straight rental activity: include all rental income and deduct rental expenses in full.

Third, the mixed-use middle ground. Your dwelling counts as a residence if your personal-use days exceed the greater of 14 days or 10% of the days rented at fair rental value. Once it is a residence, you must allocate expenses between rental and personal days, and your rental deductions cannot exceed the rental income: the activity cannot generate a tax loss. (IRC Section 280A(d), Publication 527, chapter 5.)

Illustrative example: you Airbnb a guest room 100 days and use it personally 20 days. Twenty personal days exceeds the greater of 14 days or 10% of the 100 rental days, so the dwelling is a residence: expenses get allocated between the 100 rental days and 120 total use days, and deductions stop at the rental income line. Count every personal day honestly, because use by family members counts as your personal use.

How do the Turo vehicle rules work?

Your car is listed property, and listed property has a gatekeeper test: more than 50% of its total use must be qualified business use before you can claim Section 179, bonus depreciation, or accelerated MACRS depreciation. At 50% or less business use, you are limited to straight-line depreciation under the alternative depreciation system. (IRS Publication 946.)

The IRS measures vehicle use by mileage, and it requires adequate records: the amount of each business use, the date, the business purpose, and total mileage for the year. A mileage log made at or near the time of the trip beats a reconstruction from memory every time. Allocate operating costs like gas, insurance, and repairs between business and personal miles the same way. One nuance worth knowing: the business-use requirement generally does not apply to property leased or held for leasing by someone regularly engaged in the leasing business, a facts-and-circumstances determination. An occasional Turo host is unlikely to meet that standard; a fleet operator with continuous listings is in a different position.

When does a side hustle become a business for tax purposes?

Whether your Turo or Airbnb activity is a business or a hobby changes everything about deductions. The IRS applies a facts-and-circumstances test: do you operate in a businesslike manner, keep complete records, invest time and effort, adjust methods to improve profitability, have relevant expertise, and have a history of profits? No single factor controls. (IRS hobby vs. business guidance.)

There is also a statutory presumption under IRC Section 183(d): profit in three of five consecutive years presumes the activity is for profit. Either way, hobby income is still reportable, on Schedule 1, while a genuine business reports on Schedule C with its ordinary and necessary expenses. When an activity starts as an experiment and grows into real income, upgrade your recordkeeping at the moment it turns serious, not at tax time.

What records should you keep from day one?

The Sharing Economy Tax Center (now the Gig Economy Tax Center) puts it simply: gig income is taxable even when no information return arrives. Your records are what turn gross payouts into an accurate net figure. Keep a rental calendar showing every rented day and every personal-use day for each property, a mileage log for each vehicle, receipts for all expenses, and the platform payout statements showing gross amounts before fees. Remember that a 1099-K reports gross payments, so your expense records are the only thing standing between gross and taxable.

Updated October 28, 2026.

This article is free educational content, not tax advice for your specific situation. If you want a plan built around your actual numbers, that is what our paid tax planning engagements do.