Real Estate Tax Calc
Why expense allocation matters: two different tax outcomes
When you own a vacation property that you both rent out and use personally, every shared expense — mortgage interest, property taxes, insurance, utilities, depreciation — must be split between the rental activity and the personal use. You cannot deduct 100% of these costs as rental expenses when the property serves dual purposes.
The method you use to allocate determines two things: (1) how much of each expense is deductible on Schedule E as a rental expense, and (2) how much is potentially deductible on Schedule A as a personal itemized deduction. The total expenses don't change — only the bucket they land in.
This allocation question arises only for expenses that benefit both uses: mortgage interest, property taxes, utilities, insurance, depreciation, and general repairs. Some expenses are 100% rental by their nature — advertising for tenants, property management fees, linens and supplies purchased solely for rental guests — and need no allocation. Those go entirely to Schedule E.
The stakes are meaningful. A beach house owner who rents for 80 days and uses personally for 20 days might see a $5,000 difference in deductible rental expenses depending on which allocation method applies. Multiply that by a high marginal tax rate and the choice of method matters considerably.
Which method applies: IRS §280A method vs. Tax Court method
The threshold question is whether your property qualifies as a residence under IRC §280A. A property is a residence if personal use days exceed the greater of:
- 14 days, or
- 10% of the fair rental days during the year
If personal use exceeds this threshold, the property is a residence and you must use the IRS method for shared expenses. You also face the three-tier ordering rule (see below) that prevents any net rental loss.
If personal use stays below this threshold, the property is a pure rental (not a residence), and you may choose either method. Most practitioners use the Tax Court method for non-residence properties because it places more expenses into the personal bucket, making those amounts available as Schedule A itemized deductions, while leaving less in the rental bucket.
IRS method (IRC §280A allocation): Rental allocation = rental days ÷ (rental days + personal use days). Vacant days — days when the property is neither rented nor used personally — are excluded from the denominator. This approach puts a higher percentage of shared expenses into the rental column.
Tax Court method (from Bolton v. Commissioner, 694 F.2d 556 (9th Cir. 1982)): Rental allocation = rental days ÷ 365. Vacant days are included in the denominator. This places a smaller fraction of expenses in the rental column — and more in the personal column for Schedule A treatment.
A quick numerical comparison: 80 rental days, 20 personal use days, 265 vacant days.
- IRS method rental allocation: 80 ÷ (80 + 20) = 80%
- Tax Court method rental allocation: 80 ÷ 365 = 21.9%
The IRS method results in 80% of shared expenses deducted on Schedule E as rental expenses. The Tax Court method results in only 21.9% deducted on Schedule E — but 78.1% of mortgage interest and property taxes may then flow to Schedule A as personal deductions. For a taxpayer who itemizes, the Tax Court method can produce a better overall result by boosting Schedule A deductions, even though Schedule E deductions are smaller.
Expenses that need no allocation (100% rental)
Certain expenses are directly and exclusively attributable to the rental activity and require no allocation. These go 100% to Schedule E:
- Advertising — online listing fees, classifieds, signage for rental
- Property management fees paid to a manager who handles rental bookings
- Rental commissions paid to a rental agency
- Linens, towels, cleaning supplies purchased specifically for rental guests
- Repairs made specifically for rental use — a repair scheduled between tenants and not during your personal occupancy
- Tenant credit check fees
Conversely, some expenses may be 100% personal — for example, improvements made during and exclusively for personal use periods. These get no rental allocation at all.
The three-tier ordering rule for residence-status properties
When a vacation property qualifies as a residence under §280A, deductions are allowed only up to rental income — no net rental loss is permitted. Within that cap, deductions must be taken in a specific order:
Step 1: Deduct rental-allocated property taxes and mortgage interest. These are deducted first, reducing rental income. The personal-use portion of taxes and interest goes to Schedule A. If taxes and interest alone exceed rental income (which happens when a property has heavy debt service and modest rents), only that much is deductible in the rental column — the rest of these items goes to the personal column.
Step 2: Deduct rental-allocated operating expenses. Insurance, utilities, repairs, and similar cash expenses — after allocation — are deducted next, up to any remaining rental income after Step 1. If Step 1 deductions fully absorb rental income, operating expenses are zero in Schedule E (though the personal portion of operating expenses is not deductible at all — they are simply lost).
Step 3: Deduct rental-allocated depreciation. Depreciation is taken last, and only to the extent rental income remains after Steps 1 and 2. Depreciation that cannot be used because rental income is exhausted is suspended — it is not carried forward to future years, it simply disappears. This makes depreciation the most vulnerable deduction under the residence rules and underscores why keeping personal use below the threshold matters so much.
The suspended expenses that exceed rental income are permanently lost. This is different from passive activity losses, which carry forward until you generate passive income or dispose of the property.
A full worked example with numbers
Sandra owns a beach house. In 2026, she rented it for 80 days at fair market rent ($1,500/day = $120,000 gross rental income). She used it personally for 20 days. The remaining 265 days it was vacant.
Residence test: 10% of 80 fair rental days = 8 days. Her 20 personal use days exceed both 8 and 14, so the greater threshold is 14 days. 20 > 14 → property is a residence. IRS method required; rental losses prohibited.
Annual expenses:
- Mortgage interest: $24,000
- Property taxes: $6,000
- Insurance: $3,600
- Utilities: $4,800
- Repairs: $2,000
- Depreciation (full year if 100% rental): $8,000
IRS method allocation ratio: 80 ÷ (80 + 20) = 80%
Step 1 — Taxes and interest:
- Mortgage interest: $24,000 × 80% = $19,200 rental | $4,800 personal (→ Schedule A)
- Property taxes: $6,000 × 80% = $4,800 rental | $1,200 personal (→ Schedule A)
- Rental income remaining: $120,000 − $19,200 − $4,800 = $96,000
Step 2 — Operating expenses:
- Insurance: $3,600 × 80% = $2,880 rental
- Utilities: $4,800 × 80% = $3,840 rental
- Repairs: $2,000 × 80% = $1,600 rental
- Total Step 2: $8,320
- Rental income remaining: $96,000 − $8,320 = $87,680
Step 3 — Depreciation:
- Depreciation allocated: $8,000 × 80% = $6,400
- Available rental income: $87,680 (more than enough for $6,400)
- Depreciation deducted: $6,400
- Rental income remaining: $87,680 − $6,400 = $81,280 taxable rental income
Sandra's personal deductions (if she itemizes): $4,800 mortgage interest + $1,200 property taxes = $6,000 on Schedule A. Personal portions of insurance, utilities, and repairs ($720 + $960 + $400 = $2,080) are not separately deductible — they are personal living expenses.
The 20 personal use days cost Sandra a significant chunk of otherwise deductible rental expenses. Had she kept personal use at 13 days (below the 14-day threshold), the property would not be a residence, she could use either allocation method, and a net rental loss (if any) would be available to offset other passive income.
What happens to the personal portion of allocated expenses
The personal-use portion of mortgage interest and real property taxes — determined by whichever allocation method applies — can be deducted on Schedule A as itemized deductions, subject to the usual limitations:
- Mortgage interest: Deductible on Schedule A as home mortgage interest, limited to interest on acquisition debt of up to $750,000 ($1,000,000 for loans taken before December 15, 2017). The second-home mortgage interest deduction is available for one additional residence beyond your primary home.
- Property taxes: Deductible on Schedule A, but subject to the $10,000 SALT cap ($5,000 for married filing separately) which limits the combined deduction for state and local income taxes, sales taxes, and property taxes.
The personal portions of insurance, utilities, repairs, and depreciation are not deductible anywhere — they are simply personal living expenses. Only taxes and interest have the special Schedule A treatment.
For taxpayers who take the standard deduction rather than itemizing, the personal portions of taxes and interest produce no additional tax benefit. This reinforces the importance of the property classification: if personal use exceeds the §280A threshold and the taxpayer does not itemize, the only deductions available are on Schedule E (capped at rental income), and the personal portions are wasted entirely.
Frequently asked questions
Which method do I use to allocate vacation home expenses — IRS or Tax Court?
If your property qualifies as a residence under §280A (personal use exceeds the greater of 14 days or 10% of fair rental days), you must use the IRS method: allocate by rental days divided by total occupied days (rental + personal). For non-residence rental properties, you may use either method, but the Tax Court method (rental days ÷ 365) is generally advantageous for itemizers.
What is the difference between the IRS method and the Tax Court method for vacation home expenses?
The IRS method allocates by rental days ÷ (rental + personal use days), excluding vacant days. The Tax Court method uses rental days ÷ 365. The IRS method places more expenses in the rental bucket; the Tax Court method places more in the personal bucket (potentially deductible on Schedule A for itemizers).
What is the three-tier ordering rule for vacation home deductions under §280A?
For a residence-status property: deduct rental-allocated property taxes and mortgage interest first (Step 1), then deduct rental operating expenses up to remaining income (Step 2), then rental depreciation up to remaining income (Step 3). Any excess is permanently suspended — not carried forward. The ordering prevents creating a rental loss on a residence.
What happens to the personal portion of allocated mortgage interest and property taxes?
The personal-use portion goes to Schedule A as itemized deductions, subject to the $750,000 mortgage limit and the $10,000 SALT cap on property taxes. Under the Tax Court method, more flows to Schedule A since the rental allocation is smaller, which can benefit taxpayers who itemize.
Can I deduct a vacation home rental loss if personal use exceeds the §280A threshold?
No. Once personal use exceeds the greater of 14 days or 10% of fair rental days, the property is a residence and rental deductions are capped at rental income. You cannot deduct a net loss, and excess deductions are suspended permanently — they do not carry forward to future years.
Educational information and estimates only. Not tax advice. Tax rules change and vary by situation; consult a qualified tax professional before acting.