How depreciation works for small business owners: what you need to know and what your accountant handles

When you buy a piece of equipment for your business, you cannot always deduct the full cost in the year you buy it. That is the starting point for understanding depreciation, and it is a rule with a significant exception in 2026 that every small business owner should know about before making a major purchase.

Depreciation is not a concept that requires accounting expertise to understand at the level that matters for business decisions. The part you need to know is this: the IRS has specific rules about when and how you can deduct the cost of business assets, and understanding the options puts real money back in your pocket rather than leaving it to your accountant to discover at year-end.

Why depreciation exists and what it does to your books

When your business buys something that will last more than a year, the IRS treats it differently from an ordinary expense. You are not buying a supply that gets consumed immediately. You are acquiring an asset that will generate value for the business over time, and depreciation is the mechanism for spreading the cost of that asset across the years it is useful.

Each year you own a depreciable asset, your accountant records a depreciation expense. This reduces your taxable income by the amount of the deduction without any cash leaving your business — depreciation is a non-cash expense, which is one of the reasons it appears as an adjustment on the cash flow statement rather than as a straightforward outflow.

On your balance sheet, the original cost of the asset sits in a fixed asset account. Directly below it, a separate account called accumulated depreciation tracks the total amount deducted over time. The difference between the two is the asset's net book value, or carrying value, which reflects how much of its cost has not yet been recovered through deductions.

Here is where book value and tax basis diverge, and why it matters. 

Suppose your business buys a machine for $40,000. After two years of financial-statement depreciation, say $16,000 has been recorded. The balance sheet shows a net book value of $24,000. But if that same machine qualified for a $40,000 first-year tax deduction, its adjusted tax basis could be zero even while the books show $24,000. If you then sell the machine for $20,000, your financial books suggest a $4,000 loss. The tax calculation, however, shows a $20,000 gain, because the IRS calculates gain using the amount realised less adjusted tax basis. Gain on depreciated Section 1245 property can also be ordinary income through depreciation recapture. This contrast is why your accountant maintains both a fixed-asset ledger for the books and a separate tax depreciation schedule. Before selling or trading equipment, ask for the adjusted tax basis rather than estimating the taxable result from your balance sheet.

MACRS: how depreciation normally works for tax purposes

For tax purposes, the IRS uses a system called the Modified Accelerated Cost Recovery System, or MACRS, which assigns recovery periods to different classes of property. A recovery period is a tax classification, not a prediction of exactly how long the asset will remain useful. The general MACRS schedules and the possible elections for faster deductions are separate questions.

Common recovery periods under MACRS include:

Within each recovery period, MACRS uses accelerated rates that front-load deductions into the early years. For a five-year asset, the first-year rate under the standard half-year convention is 20%, followed by 32% in year two, 19.2% in year three, and declining percentages thereafter across six calendar years. IRS Publication 946 contains the complete class-life tables and applicable rates.

A critical point: the recovery class determines the baseline schedule, while elections and exceptions determine whether eligible cost is deducted faster. Have your accountant identify the correct asset class rather than guessing from the purchase price or the asset's name.

Section 179: deduct the full cost in year one, subject to an income test

Section 179 of the tax code allows businesses to elect to expense qualifying property in the year it is placed in service, rather than recovering that cost gradually through the MACRS schedule. For tax years beginning in 2026, the maximum Section 179 deduction is $2,560,000, with the deduction reducing dollar-for-dollar once total qualifying property placed in service exceeds $4,090,000. Eligible property includes most tangible personal property used in the business, qualifying off-the-shelf computer software, and certain improvements to nonresidential real property. Standard passenger automobiles are subject to additional limits covered below.

The key constraint on Section 179 is an active-business income test: the deduction generally cannot exceed your taxable income from active trades or businesses for the year, so you cannot use it to create a tax loss. Any amount disallowed by the income test carries forward to future years where it can offset business income.

A practical example: if your business places $60,000 of eligible equipment in service in 2026 and your relevant active-business income is $90,000, you can elect to deduct the full $60,000, reducing taxable income to $30,000. If your relevant income were $40,000, an election covering the full $60,000 would permit $40,000 now and carry $20,000 forward. Actual Section 179 income calculations can reflect multiple active businesses and other adjustments, so the final number requires your accountant's review.

Section 179 is an election, not a requirement to deduct the largest possible amount. A business that needs to preserve income in the current year, or that expects higher income in future years where a deduction would be more valuable, may choose not to elect the full amount.

Bonus depreciation in 2026: the change that matters most

Bonus depreciation is a first-year deduction that differs from Section 179 in one important way: it is not subject to an active-business income ceiling. Bonus depreciation can contribute to a net operating loss, which then carries forward to offset future income.

The history matters here. Under the Tax Cuts and Jobs Act, bonus depreciation was phasing down: 80% in 2023, 60% in 2024, and 40% for property acquired before January 20, 2025. The One Big Beautiful Bill Act, signed in July 2025, permanently restored 100% additional first-year depreciation for qualified property acquired after January 19, 2025, provided the asset also meets the applicable placed-in-service rules.

This means an older purchase does not become eligible for the restored 100% rate simply because it first enters service in 2026. The acquisition date is what determines which bonus-depreciation rate applies. A written binding contract can determine when property is treated as acquired, so a delivery invoice alone may not settle the question. When both Section 179 and bonus depreciation are available for the same asset, Section 179 is applied first, and bonus depreciation applies to the remaining eligible basis.

One important trade-off: if bonus depreciation creates a net operating loss, the future use of that NOL is generally limited to offsetting 80% of taxable income in any given year. Whether that limitation matters depends on your projected future income and your entity's tax rules.

Vehicles require a separate calculation

Passenger automobiles placed in service in 2026 are subject to specific annual depreciation limits under the listed property rules. For a qualifying passenger automobile placed in service during calendar year 2026, the first-year depreciation ceiling is $20,300 when bonus depreciation applies, or $12,300 when it does not. These limits govern the combined deduction including any Section 179 and bonus amounts; they are not separate allowances that can be added together.

Heavier vehicles classified as SUVs with a gross vehicle weight rating over 6,000 pounds and up to 14,000 pounds are not subject to the passenger automobile caps, but their Section 179 deduction is capped at $32,000 for tax years beginning in 2026. This SUV limit is a Section 179 restriction, not necessarily a ceiling on every first-year deduction: bonus depreciation may apply to eligible remaining basis. Certain purpose-built trucks and vans with specific cargo or seating configurations have exceptions from the heavy-SUV limit; the configuration details matter.

The vehicle's weight alone does not determine its tax classification or guarantee a full deduction. Business-use percentage also matters: deductions are limited to the portion of use that is genuinely for business. Keep a contemporaneous mileage log recording the date, destination, business purpose, and miles of each business trip.

What you supply, what your accountant calculates

Your accountant has the rules. You have the facts. The most valuable handoff happens before year-end, while purchase and installation dates can still affect which tax year receives a deduction.

For a calendar-year business, an asset must be ready and available for its intended business use in 2026 to begin depreciation in 2026. Paying for it before December 31 is not sufficient on its own if the asset is not yet placed in service. The service date is what triggers the deduction, not the payment date.

What you should bring to your accountant before making a significant purchase: the invoice, the expected delivery and ready-for-use date, the business-use estimate (and actual mileage records for vehicles), and any contracts or financing agreements. What your accountant determines: the asset's correct MACRS class, basis, applicable convention, Section 179 eligibility, bonus depreciation eligibility, and the depreciation schedule going forward. At disposal, provide the sale or trade-in documents, and your accountant will calculate adjusted tax basis, gain or loss, and any recapture.

The best question before a purchase is not "Can I write off all of it?" but "Which deduction is available, when can I use it, and what happens when I sell the asset?"

How Inkle helps

Inkle Books describes a fixed assets functionality that syncs financial accounts, records depreciation, and supports the monthly close with a dedicated bookkeeper reviewing transactions. That bookkeeping layer maintains the financial-statement depreciation records and the fixed-asset ledger through each month-end close.

Inkle Tax provides CPA-supported federal and state tax preparation. For a business considering an equipment or vehicle purchase, the right conversation happens before the purchase: bring your invoice, expected service date, business-use estimate, and projected income to your Inkle accountant so the most appropriate deduction strategy can be identified in advance rather than reconstructed after the fact.

Inkle handles bookkeeping and tax for owner-operated businesses across the US. See how it works or book a demo to talk through what your business needs.