How to use Form 3115 to catch up on missed depreciation

Most startups that have been using the wrong depreciation method for a few years share the same instinct when they find out: they assume they need to file amended returns for every affected year. In practice, that is rarely the right approach, and often not necessary at all.

The IRS has a cleaner mechanism for this. If a business has been using an impermissible depreciation method, or has simply been claiming less depreciation than it was entitled to, it can file Form 3115 to formally switch to the correct method and claim the entire accumulated shortfall in a single year. All of those unclaimed deductions, across every prior year the error existed, get recognized at once in the year of change through a single catch-up adjustment.

For a startup that has been underclaiming depreciation for several years on computers, software, leasehold improvements, or other business assets, the size of that adjustment can be substantial. And because the catch-up reduces taxable income in the year it is taken, the benefit arrives immediately rather than being spread across multiple years.

Why depreciation errors are more common than founders expect

Depreciation is one of those areas of tax that looks simpler than it is. The basic idea is intuitive: a piece of equipment that costs $10,000 and lasts five years does not generate a $10,000 deduction in year one. Instead, the cost is spread across the asset's useful life, and the IRS prescribes the exact schedule for that spreading through a system called MACRS, the Modified Accelerated Cost Recovery System.

Where it gets complicated is in the details. Different categories of assets have different recovery periods. Five-year property, seven-year property, fifteen-year property, and thirty-nine-year property are all treated differently. The convention used to determine when depreciation starts (half-year, mid-quarter, or mid-month) affects the calculation. Bonus depreciation rules have changed repeatedly and interact with the MACRS schedule in ways that are easy to misapply. And the distinction between what counts as personal property versus a structural component of a building, which determines whether an asset goes on the five-year or thirty-nine-year schedule, requires a level of analysis that many startup accountants do not apply systematically on the first pass.

The result is that a significant portion of startups have been claiming either too little depreciation, because they placed an asset in the wrong recovery period or failed to apply available bonus depreciation, or too much, because they used a method that was not permissible for their situation. Either error, if it has appeared on two or more consecutively filed tax returns, triggers the Form 3115 correction requirement.

What the IRS says about correcting depreciation errors

IRS Publication 946, which governs how businesses depreciate property, addresses this directly. For a business that changes from an impermissible method of determining depreciation to a permissible one, the IRS allows a Section 481(a) adjustment for any unclaimed or excess amount of allowable depreciation. That adjustment captures the cumulative difference between what was claimed under the old method and what would have been claimed under the correct method, starting from the first year the error appeared.

The IRS also specifies the situations that require Form 3115 for a depreciation change. A change from an impermissible method used on two or more consecutively filed returns is one. A change in the treatment of an asset from nondepreciable to depreciable, or from depreciable to nondepreciable, is another. A change in the depreciation method, recovery period, or convention of a depreciable asset is a third. All of these are handled through Form 3115, not through amended returns.

The reason the IRS prefers this structure is consistency. Amended returns reach back into closed tax years and create reconciliation complexity in both directions. Form 3115 moves forward: the old returns stay as they are, the catch-up adjustment lands in the current year, and everyone agrees on the new method going forward.

How the catch-up adjustment actually works

When a startup has been underclaiming depreciation for three years on an asset that should have been on a five-year MACRS schedule, the Section 481(a) adjustment is the total of the depreciation that should have been claimed in those three years but was not. That total is a negative adjustment, meaning it reduces taxable income in the year of change.

Per IRS Publication 946 and the Form 3115 instructions, a negative Section 481(a) adjustment is taken in full in the year of change. It is reported as an other expense deduction on the business tax return. There is no spreading, no installment, no waiting. The full accumulated shortfall becomes available in the year the Form 3115 is filed.

A positive Section 481(a) adjustment works differently. If the business has been claiming too much depreciation and needs to give some back, the adjustment increases taxable income. The IRS generally allows that increase to be spread over four tax years. For a positive adjustment under $50,000, the business can elect a one-year adjustment period instead, which means the full amount is recognized in the year of change rather than spread across four years. The election is made by completing the appropriate line on Form 3115.

One detail worth understanding clearly: the Section 481(a) adjustment does not give the business a refund for overpaid taxes in prior years. It gives the business a current-year deduction equivalent to what it should have been able to claim before. If the business was profitable in year one and is losing money in year four, the catch-up deduction in year four may have limited immediate value depending on the overall tax position. A tax advisor can model the after-tax impact before deciding when to file the method change.

The audit protection that comes with a clean Form 3115 filing

One of the most undersold benefits of filing Form 3115 correctly for a depreciation correction is the audit protection it provides. When an automatic method change is granted under the applicable revenue procedure, audit protection generally applies, meaning the IRS will generally not reopen the prior years covered by the change for that same issue. This protection is subject to exceptions: some changes do not receive it at all, and a single Form 3115 can contain items with different audit-protection results. The old returns stay closed on that item.

If a startup simply starts using the correct depreciation method without filing Form 3115, none of that protection exists. The IRS can examine any open year, find the depreciation inconsistency, and require the business to revert to its old method and pay the difference, along with interest. The audit protection that comes with a properly filed Form 3115 is a meaningful shield, and it is one of the reasons that fixing a depreciation error through this mechanism is almost always preferable to either doing nothing or filing amended returns for the affected years.

The specific situations this applies to for startups

Depreciation catch-up corrections come up most frequently in a few specific scenarios for early-stage companies.

Wrong recovery period for equipment and computers: Computers and their peripheral equipment are five-year MACRS property. Office furniture and fixtures are seven-year property. Leasehold improvements in a commercial space are fifteen-year property under the qualified improvement property rules. If a startup's accountant placed any of these assets on the wrong schedule, perhaps treating computers as seven-year property or office improvements as thirty-nine-year property, the depreciation claimed in each year is lower than it should be, and the cumulative shortfall is recoverable through a Form 3115 catch-up.

Failure to apply bonus depreciation: Bonus depreciation allows businesses to deduct a significant percentage of an eligible asset's cost in the year it is placed in service, rather than spreading the deduction across the recovery period. The applicable percentage has changed several times under tax legislation, including most recently under the One Big Beautiful Bill Act signed July 4, 2025, which reinstated a permanent 100% additional first-year depreciation deduction for qualified property acquired after January 19, 2025. A startup that placed eligible assets in service in prior years and was not advised to claim available bonus depreciation, or that claimed the standard MACRS percentage instead, may have an unclaimed deduction worth investigating.

One important qualification: a missed bonus depreciation claim is not always correctable through a standard Form 3115 method change. IRS Publication 946 distinguishes between a change from not claiming a special depreciation allowance and a late election for bonus depreciation. A late election is generally not treated as an ordinary accounting method change, and the IRS points instead to limited amended-return relief or a ruling request in those situations. Whether Form 3115 is the right vehicle depends on the specific asset, the tax year, the election that was or was not made, and the applicable transition rules. Confirm with a tax advisor before assuming a Form 3115 catch-up applies to a missed bonus depreciation claim.

Assets incorrectly classified as non-depreciable: Some assets that appear to be non-depreciable on the surface are actually eligible for depreciation under the correct analysis. Certain depreciable computer software has a 36-month straight-line recovery period under MACRS, though the software's legal and factual character must be determined before assuming depreciability. If these were not deducted at all, the depreciation analysis depends on whether the software meets the applicable definition and recovery rules for the specific tax year.

Tangible property regulations compliance: The IRS's tangible property regulations, finalized in 2013 and effective for tax years beginning 2014, changed how businesses distinguish between repairs (currently deductible) and improvements (capitalized and depreciated). Startups that were capitalizing and depreciating expenditures that should have been deducted as repairs, or the reverse, may need a Form 3115 to align with the correct treatment under those regulations.

What completing Schedule E actually involves

Form 3115 includes Schedule E specifically for depreciation and amortization changes. Unlike the overall method change in Schedule A, which addresses cash-to-accrual switches and similar overarching changes, Schedule E is an asset-by-asset document. The preparer identifies each item of property for which a change is being requested and provides specific information for each one.

For each asset, Schedule E captures the property description and type, the year it was placed in service, its use in the business, the depreciation method being changed from, the depreciation method being changed to, any tax credit claimed on the property, and the Section 481(a) adjustment attributable to that specific asset. The instructions require attaching a statement describing the property and explaining all of these elements.

For a startup with multiple affected assets, this means the preparation of Schedule E is a more detailed exercise than a simple overall method change. Each asset's history needs to be traced from its placed-in-service date, and the correct depreciation under the new method needs to be calculated for each prior year to arrive at the catch-up amount. This is exactly the kind of work where having a tax team that knows the specific rules for each asset class matters, and where errors in the schedule itself can cause the Form 3115 to be rejected or questioned.

The one situation where Form 3115 does not apply

It is worth being explicit about what Form 3115 does not cover in the depreciation context. If a startup claimed depreciation using a method that was permissible, and now wants to change to a different permissible method, the Section 481(a) adjustment is zero. There is no catch-up because both methods were valid, and the IRS does not provide a benefit for switching between two acceptable approaches.

The IRS instructions are also specific about what does not require Form 3115 at all. Elections under Section 167, 168, 179, or 197 are made or revoked through different mechanisms, not through Form 3115. Changing a placed-in-service date is not an accounting method change. Changing the salvage value is not covered unless the salvage value is being changed to zero when zero is specifically prescribed by the relevant Code section.

The trigger for a Form 3115 depreciation correction is a change from a method that was impermissible, meaning one that was not allowed under the applicable rules, to one that is. If the previous method was permissible, Form 3115 may still be required to switch methods, but the catch-up adjustment that makes this so valuable for recovering missed deductions only arises from the impermissible-to-permissible change.

How Inkle handles this

Inkle handles Form 3115 depreciation corrections for US startups as a flat $200 filing, a one-time fee that covers the preparation and submission of the form, including the Schedule E asset-level analysis and the Section 481(a) catch-up calculation.

The process from the founder's side is straightforward. You tell Inkle which assets are involved and what depreciation method has been used. Inkle identifies the correct method, calculates the accumulated shortfall across all prior years, prepares the Schedule E detail, and handles the filing, including both the original attached to the tax return and the required duplicate copy sent to the IRS. You review and approve, and the filing goes out.

Because Inkle's bookkeeping and tax records sit on the same platform, the asset data needed to prepare Schedule E is already in the system for most clients. There is no back-and-forth to reconstruct a depreciation schedule that should have been maintained throughout.

Learn more about how Inkle handles accounting method changes.

Frequently asked questions

What is a depreciation catch-up deduction? 

A depreciation catch-up deduction is the accumulated depreciation that a business was entitled to claim under the correct method but did not, because it was using an impermissible method. When a business files Form 3115 to correct the method, the total unclaimed depreciation from all prior years becomes available as a single deduction, called a negative Section 481(a) adjustment, in the year of the method change.

Do I need to file amended returns to fix a depreciation error?

 No, in most cases. If the incorrect depreciation method appeared on two or more consecutively filed returns, the correction is made prospectively through Form 3115, not through amended returns. The old returns stay as filed, and the accumulated shortfall is deducted in the current year through the Section 481(a) catch-up adjustment.

How much can I recover through a depreciation catch-up? 

It depends on the assets involved, the number of years the error persisted, and the difference between what was claimed and what should have been claimed. For a startup with several years of computers, equipment, or leasehold improvements on the wrong schedule, the catch-up can be tens of thousands of dollars in additional deductions, all recognized in the year of the Form 3115 filing.

Can I use Form 3115 if I missed bonus depreciation? 

Sometimes, but not always. A missed bonus depreciation claim must be analyzed before assuming Form 3115 applies. IRS Publication 946 distinguishes between a change from not claiming a special depreciation allowance and a late bonus depreciation election. A late election is generally not an ordinary accounting method change and may require amended-return relief or a ruling request instead. Whether Form 3115 is the right path depends on the specific asset, tax year, and election rules. A tax advisor should confirm the correct approach before filing.

Does filing Form 3115 for a depreciation correction protect me from an IRS audit on those prior years? 

Generally yes. When an automatic method change is granted, the IRS's audit protection provision under Rev. Proc. 2015-13 means it will generally not reopen the prior years covered by the change for that same depreciation issue. A startup that has been claiming the wrong depreciation method without filing Form 3115 does not have this protection, and those years remain open for examination on that issue.