Form 3115 Preparation: Claim Missed Depreciation on Your Airbnb

The "Catch-Up" Opportunity

If you purchased your short-term rental more than one year ago and have been depreciating it using the standard straight-line method, you have likely been leaving significant deductions on the table.

Form 3115 (Application for Change in Accounting Method) allows you to retroactively apply cost segregation results to your property and claim all of the missed accelerated depreciation in a single tax year. This is the Section 481(a) adjustment.

The result: a lump-sum deduction in the current year that reflects all prior years of under-depreciation. For a property purchased several years ago, this can represent a six-figure tax benefit realized immediately.

No Amended Returns Required

This is the most misunderstood aspect of cost segregation for existing properties. You do NOT need to amend prior year tax returns. The entire adjustment — every dollar of missed depreciation from every prior year — is taken on the current year return via the Section 481(a) adjustment.

Retroactive Cost Segregation

The process is straightforward:

1. We perform a cost segregation study on your property as if it were placed in service today
2. We calculate the depreciation that should have been taken in each prior year under the accelerated schedules
3. We compare that to the depreciation that was actually taken (straight-line)
4. The difference is the Section 481(a) adjustment — your lump-sum catch-up deduction

This methodology applies regardless of when the property was purchased. Whether you bought it 2 years ago or 10 years ago, the catch-up calculation captures all missed depreciation.

The underlying study follows the same rigorous methodology as our standalone detailed engineering studies. You can estimate potential savings using our calculator before committing.

Correcting Depreciation Errors

Form 3115 isn't only for switching from straight-line to cost segregation. It's also used to correct previously misclassified assets.

Common errors we identify:

• Land improvements (driveways, fencing, landscaping) depreciated over 27.5 or 39 years instead of 15 years
• Personal property (appliances, furniture, window treatments) depreciated as part of the building structure
• Qualified Improvement Property (QIP) not properly classified for 15-year treatment and bonus depreciation
• Failure to apply bonus depreciation to eligible assets in the year placed in service

Each of these errors results in under-depreciation that can be corrected and recaptured through a single Form 3115 filing.

If your property is a short-term rental, you may also qualify for the STR Loophole, allowing these recaptured losses to offset your W-2 income. Consider our STR Loophole Package for a comprehensive approach.

Audit Protection & Compliance

Filing Form 3115 is not optional — it is required when changing your accounting method for depreciation. The filing serves two purposes:

1. It formally notifies the IRS of the change, establishing compliance
2. It provides audit protection by documenting the methodology and calculations

A properly prepared Form 3115 with a supporting cost segregation study is your documentation package. It demonstrates that the change was made in accordance with IRS procedures and that the underlying asset classifications are supported by engineering analysis.

We prepare Form 3115 in coordination with your CPA to ensure it is filed correctly, timely, and with all required supporting documentation.

Link to bonus depreciation to check your bonus depreciation rate. Link to contact to discuss your property.