12 Common Landlord Tax Mistakes That Cost Thousands (And How to Avoid Them)

Are You Leaving Money on the Table?

The IRS estimates that rental property owners overpay their taxes by billions of dollars each year — not because the tax code is against them, but because they make avoidable mistakes. Some mistakes cost a few hundred dollars. Others cost tens of thousands.

Here are the 12 most common (and most costly) landlord tax mistakes, ranked by financial impact, and exactly how to fix each one.

1. Not Taking Depreciation (or Taking It Wrong)

Typical cost: $5,000–$20,000+ per year

Depreciation is the single largest tax deduction available to rental property owners, yet many landlords either skip it entirely or calculate it incorrectly. Here is what goes wrong:

Not depreciating at all: Some new landlords do not realize they are required to depreciate their rental property. The IRS treats depreciation as "allowed or allowable" — meaning even if you do not claim it, they will recapture it when you sell as if you had.
Depreciating the land: Only the building is depreciable, not the land. Allocate based on your county tax assessment or an appraisal. A common split is 75-80% building, 20-25% land.
Wrong placed-in-service date: Depreciation starts when the property is available for rent, not when you purchased it or when you found a tenant.
Missing bonus depreciation: Under the OBBBA (effective January 20, 2025), qualifying property components are eligible for 100% bonus depreciation. Without a cost segregation study, you are depreciating these components over 27.5 years instead of expensing them immediately.

Fix: Claim depreciation every year. If you missed it in prior years, file Form 3115 (Change in Accounting Method) to catch up — no amended returns needed. Consider a cost segregation study for properties worth $300,000+.

2. Misclassifying Repairs as Improvements (or Vice Versa)

Typical cost: $1,000–$10,000 per year

This is the most common audit trigger for rental property owners. The distinction matters because repairs are deducted immediately while improvements must be capitalized and depreciated over 27.5 years.

Repair (deduct now): Fixing a leaky faucet, patching a roof, repainting a room, replacing a broken window, unclogging a drain
Improvement (capitalize): New roof, kitchen remodel, adding a bathroom, replacing all the plumbing, new HVAC system

The IRS uses three tests: Does it better the property? Does it restore it? Does it adapt it to a new use? If yes to any, it is likely an improvement.

Fix: Use the de minimis safe harbor to expense items under $2,500 each (or $5,000 with audited financial statements). Document the nature of every repair with photos and descriptions.

3. Not Tracking Mileage and Travel

Typical cost: $500–$3,000 per year

Every trip to your rental property for management, maintenance, or inspections is deductible. The 2025 standard mileage rate is $0.70 per mile. If you drive 20 miles round-trip to your property twice a month, that is 480 miles × $0.70 = $336 in deductions — and most landlords drive more than that.

Also deductible:

Trips to the hardware store for rental supplies
Driving to meet contractors, tenants, or your property manager
Travel to view potential investment properties (once you are an active investor)
Out-of-town travel for distant properties (airfare, hotel, 50% of meals)

Fix: Use a mileage tracking app (MileIQ, Everlance, or just a spreadsheet). Log the date, destination, purpose, and miles for every rental-related trip. The IRS requires contemporaneous records.

4. Forgetting to Deduct the Closing Costs

Typical cost: $2,000–$8,000 (one-time)

When you purchase a rental property, many closing costs are deductible or depreciable — but landlords often forget them:

Loan origination fees / points: Amortized over the life of the loan
Title insurance, recording fees, transfer taxes: Added to your cost basis (reducing future capital gains)
Prepaid property taxes and interest: Deductible on Schedule E in the year paid
Appraisal fees: Added to cost basis
Legal fees for the purchase: Added to cost basis

Fix: Review your closing statement (HUD-1 or Closing Disclosure) and allocate every line item. Your cost basis is purchase price plus capitalizable closing costs minus land value.

5. Commingling Personal and Rental Expenses

Typical cost: $1,000–$5,000 per year (in lost deductions or audit exposure)

When you mix personal and rental expenses in the same bank account, you lose track of deductible expenses and create audit risk. Common problems:

Using a personal credit card for rental repairs and forgetting to log them
Paying rental expenses from a personal account without documentation
Not separating expenses when a property is partially personal use

Fix: Open a dedicated bank account and credit card for your rental business. Run all rental income and expenses through these accounts. This alone can increase your claimed deductions by 15-20% because you stop losing receipts.

6. Not Deducting a Home Office

Typical cost: $500–$1,500 per year

If you manage your rental properties from a dedicated space in your home, you likely qualify for the home office deduction. Many landlords assume this is only for self-employed professionals — it is not.

The simplified method gives you $5 per square foot, up to 300 square feet = $1,500 per year with zero record-keeping beyond measuring your office space.

Fix: Measure your dedicated workspace. If you regularly use it for rental management (bookkeeping, tenant communication, research), claim the deduction on Schedule C or directly on Schedule E depending on your situation.

7. Reporting Security Deposits as Income (When They Are Not)

Typical cost: $500–$2,000 per year

Security deposits are not rental income when received — they become income only when you keep them (for damage or unpaid rent). Many landlords mistakenly report the full deposit as income in the year received, then fail to deduct the return of the deposit later.

Deposit received and held: Not income yet
Deposit applied to last month's rent: Income in the year applied
Deposit kept for damages: Income in the year you decide to keep it, but you can deduct the repair cost

Fix: Track deposits separately. Only report them as income in the year they are forfeited or applied to rent.

8. Missing the Passive Activity Loss Rules

Typical cost: $2,000–$25,000+ per year (in deferred deductions)

Rental real estate is generally treated as a passive activity, which means losses can only offset other passive income unless you qualify for an exception:

Active participation exemption: Deduct up to $25,000 in rental losses against non-passive income if your MAGI is under $100,000 (phases out completely at $150,000)
Real Estate Professional status: All rental losses become non-passive if you spend 750+ hours in real property trades/businesses and more time in real estate than anything else
Short-term rental loophole: If average guest stays are 7 days or less and you materially participate, losses are non-passive under the STR loophole

Fix: Track your hours. If you are close to qualifying for Real Estate Professional status or STR material participation, the difference can be worth tens of thousands in current-year deductions.

9. Ignoring the QBI / Section 199A Deduction

Typical cost: $1,000–$10,000+ per year

The Section 199A qualified business income deduction allows eligible landlords to deduct up to 20% of their net rental income. Made permanent by the OBBBA, many landlords either do not know about it or assume rental income does not qualify.

To qualify, you can use the IRS Safe Harbor (Rev. Proc. 2019-38): maintain separate books, log 250+ hours of rental services per year, and keep records. Alternatively, if your taxable income is under $191,950 (single) or $383,900 (married filing jointly) for 2025, you qualify without the safe harbor.

Fix: Track your rental management hours. If you spend 250+ hours managing your properties, claim the safe harbor. The deduction is worth 20% of your net rental income.

10. Not Issuing 1099s to Contractors

Typical cost: $0–$5,000 (in denied deductions)

If you pay an independent contractor $2,000 or more in 2026 (the new threshold under OBBBA, previously $600), you must issue Form 1099-NEC by January 31, 2027. For 2025 returns, the threshold was $600.

Failure to issue 1099s can result in:

$60–$310 penalty per form (depending on how late)
The IRS may disallow the deduction entirely if they cannot verify the payment

This applies to property managers, handymen, plumbers, electricians, landscapers, cleaners, and any other non-employee service providers.

Fix: Collect W-9 forms from every contractor before you pay them. Use accounting software or a payroll service to generate 1099s automatically.

11. Not Deducting Insurance Premiums

Typical cost: $500–$3,000 per year

Landlords often deduct their basic landlord insurance policy but miss additional deductible insurance costs:

Umbrella liability policies (the rental property portion)
Flood insurance (required in some zones, deductible regardless)
Earthquake or wind/hail riders
Rent guarantee insurance
Workers' compensation (if you have employees)
Professional liability / E&O insurance (for property managers)

Fix: Review all insurance policies that cover your rental properties. Allocate the rental portion of any shared policies (like an umbrella policy covering both personal and rental assets).

12. Not Keeping Adequate Records

Typical cost: Potentially all of the above

Without documentation, every other deduction on this list is at risk. The IRS can disallow any deduction you cannot substantiate. The standard of proof is on you.

What the IRS expects:

Receipts for all expenses over $75
Bank and credit card statements showing rental-related transactions
Mileage logs with dates, destinations, and business purpose
Lease agreements documenting rental terms and income
Photos and descriptions of repairs (to distinguish from improvements)
Time logs if claiming Real Estate Professional status, STR material participation, or Section 199A safe harbor

Fix: Use a dedicated bank account, save digital receipts, and log your hours weekly (not at year-end from memory). Cloud-based tools like Stessa, Baselane, or REI Hub make this nearly automatic.

How Much Are These Mistakes Costing You?

Mistake	Typical Annual Cost
Not taking depreciation	$5,000–$20,000+
Misclassifying repairs	$1,000–$10,000
Not tracking mileage	$500–$3,000
Missing closing cost deductions	$2,000–$8,000 (one-time)
Commingling expenses	$1,000–$5,000
Skipping home office deduction	$500–$1,500
Misreporting security deposits	$500–$2,000
Ignoring passive loss rules	$2,000–$25,000+
Missing QBI deduction	$1,000–$10,000+
Not issuing 1099s	$0–$5,000
Missing insurance deductions	$500–$3,000
Poor record-keeping	All of the above

A landlord making just three or four of these mistakes could be overpaying by $10,000–$30,000 per year.

Next Steps

Use the RentalDeductions calculator to estimate your depreciation and see if you are claiming the right amount
Review the April 15 deadline checklist to catch any last-minute deductions
If you need more time, file a tax extension before April 15
Order a cost segregation report to maximize your depreciation deductions
Read our Schedule E filing guide for step-by-step filing instructions