Tax rules cover what expenses can be deducted and when—in what year—they can be deducted. Some types of expenditures are deductible in full the year they're incurred, but others must be taken over a number of years.
The first category is called "current expenses," and the second is "capital" or "capitalized expenditures." You need to know the difference between the two and the tax rules for each type of expenditure.
We'll try to make it easy on you, but some gray areas exist.
Generally, current expenses are everyday costs of keeping your business going, such as the rent and electricity bills. Rules for deducting current expenses are fairly straightforward. You subtract the amounts spent from your business's gross income in the year the expenses were incurred—that is, the year you paid for them if you're a cash basis business as most small businesses are.
Other business expenditures, such as the cost of equipment, land, and vehicles, to name a few, can't be deducted in the same way as current expenses. Because they're expected to generate revenue in future years, asset purchases are treated as investments in your business.
They must be deducted over a number of years, or "capitalized," as specified in the tax code (with certain important exceptions—bonus depreciation and Section 179—discussed below). This, theoretically, allows the business to more clearly account for its profitability from year to year. The general rule is that if an item has a useful life of one year or longer, it must be capitalized.
The deduction taken over a number of years is usually called "depreciation," but in some cases, it's called an "amortization expense." All of these words describe the same thing: writing off or depreciating asset costs through annually claimed tax deductions.
Many rules apply to how different types of assets must be written off. The tax code dictates both absolute limits on some depreciation deductions, and over how many future years a business must spread its depreciation deductions for all asset purchases. Businesses, large and small, are affected by these provisions. (IRC §§ 167, 168, and 179.)
A special depreciation deduction called "bonus depreciation" is available for new qualified property. Bonus depreciation allows taxpayers to deduct in a single year a specified percentage of a long-term asset's cost in the first year the property is placed in service.
Starting September 27, 2017 through January 1, 2023, you can deduct 100% of the cost of eligible property using first-year bonus depreciation. After that, bonus depreciation will decrease as follows:
Bonus deduction can be taken in addition to Section 179, although additional restrictions apply to its use.
Another tax break creating an exception to the long-term write-off rules is found in IRC Section 179. A small business can write off in one year most types of its capital expenditures, up to $1,080,000 (2022). This deduction is subject to a phase-out after you reach $2,700,000 (2022) or more of eligible Section 179 expenditures.
Some assets don't qualify for this deduction, like real estate, inventory bought for resale, and property bought from a close relative. For more information on bonus depreciation and Section 179, see Bonus Depreciation Extended Through 2026 Under the Tax Cuts and Jobs Act.
Normal repair costs, such as fixing a broken copy machine or a door, are current expenses, so they can be deducted in the year incurred. On the other hand, the cost of making improvements to a business asset must be capitalized if the enhancement:
"Improvements" usually refers to real estate—for example, putting in new electrical wiring, plumbing, and lighting—but the rule also applies to rebuilding business equipment.
For more details on deducting expenses, as well as information on how to avoid audit triggers, see Deduct It! by Stephen Fishman (Nolo) and Tax Savvy for Small Business by Frederick W. Daily and Stephen Fishman (Nolo).