Section 179 lets a small business deduct the full cost of qualifying property, computers, office equipment, off-the-shelf software and certain building improvements, in the year the property goes into service, instead of depreciating it over several years. For a three to twenty person service firm the 2026 dollar limit of $2,560,000 is rarely the number that holds you back; the cap at the business's own taxable income is. The date is the catch: the deduction follows the year the property is ready and available for its specific use, which may be a different year from when you ordered it or wrote the check. This is general information, not tax advice; the figures were checked in September 2026 and apply to the 2026 tax year, and a purchase large enough to matter belongs in front of your CPA.
What Section 179 does
Section 179 is an election. You complete Part I of Form 4562 with your return, list the property, and take the deduction. Because it is an election, you can still make it on a late-filed original return, and you can make or revoke it on an amended return filed within the time the law allows. The paperwork can be late; the property still has to have been in service by the end of the tax year.
Your records start with the election. The guidance expects records identifying each item, who you bought it from, and when you placed it in service. A firm that buys a laptop in November and a used printer in December and keeps the invoices and delivery dates has done most of the work before the return is written.
What qualifies for a service business
The election covers tangible personal property. The IRS defines that as any tangible property that is not real property: machinery, equipment, office furniture, testing equipment, signs. For a service firm, that is the everyday list.
Off-the-shelf software qualifies with three conditions. It has to be available to the general public, licensed non-exclusively, and not substantially modified. The rule describes purchased software; the guidance does not extend the election to a monthly subscription.
The election also reaches qualified improvement property. That means interior improvements to a nonresidential building made after the building itself was placed in service. Four building systems are named specifically: roofs, HVAC, fire protection and alarm systems, and security systems, as long as they go into nonresidential real property. Most firms of three to twenty rent their space, so this part of the rule mostly reaches the one or two of you who own it.
On top of the property list, three conditions apply. The property has to be acquired by purchase. Equipment you received as a gift or inherited falls outside the rule, and buying from a related person disqualifies the purchase. The IRS's own example is a tailor who bought sewing machines from his father and could not deduct them. You can only elect Section 179 on property you use more than 50 percent for business in the year you put it in service, and you deduct only the business percentage of the cost. The IRS's example is an $11,000 item used 80 percent for business, which gives you $8,800 of qualifying cost.
Vehicles cap their own value. A heavy sport utility vehicle is capped at $32,000 under Section 179 in 2026. An ordinary passenger car bought in 2026 is capped at $20,300 in the first year when bonus depreciation applies and $12,300 when it does not, no matter what the car cost, and that cap covers the Section 179 deduction and depreciation together. A car is not a way around the limit.
Exhibit 1
Equipment, furniture, computers and purchased software qualify, and a software subscription does not.
The 2026 limit will not bind you
For a tax year beginning in 2026 you can elect to expense up to $2,560,000 of qualifying property under Section 179, and the limit starts shrinking dollar for dollar once you place more than $4,090,000 of Section 179 property in service in the year. Those are industrial-scale numbers. A twenty-person service firm that buys every computer, desk and camera it might want in one December is spending a small fraction of the limit. The number that holds you back is the next one, measured against your own income.
The limit that actually bites
Section 179 cannot push you into a loss. Your deduction stops at the taxable income from the active conduct of your trade or business, and anything above that carries to the next year. The dollar limit applies to you as a taxpayer, covering all of your businesses together under one cap.
In a good year the limitation does nothing. In a thin year it does everything. A firm in its first year, or one whose bookings slipped in the back half, can place a year's worth of equipment in service and have part of the deduction carried forward. The deduction lands in next year's return instead of this one. The carryover is a change of when the deduction is used, not a loss of it. But if the purchase was made to use the deduction this year, a thin year quietly converts the plan into next year's problem. The whole cost is spent this year, and part of the saving is deferred.
When the books are current, you know roughly where taxable income lands before you sign the purchase order; that is the monthly bookkeeping rhythm doing its work. A firm that cannot forecast December is guessing at the Section 179 test.
Bonus depreciation, the parallel route
Separately from Section 179, 100 percent bonus depreciation is now permanent for qualifying property acquired after January 19, 2025, and it covers used property as well as new. Bonus depreciation is the default. Unless you elect out, you must take the 100 percent allowance on qualifying property. The IRS's guidance so far is Notice 2026-11, which is interim. Proposed regulations are still to come, so this is the one part of the picture most likely to shift before the rules settle.
For a firm well under the Section 179 limit the two routes reach the same federal result, and the state return is where they stop agreeing, which is where the choice actually lives for most small service firms.
Below the big-ticket purchases there is a third, simpler route. The de minimis safe harbor lets a business without an applicable financial statement deduct up to $2,500 per invoice or per item outright. To use it you need a consistent accounting policy in place at the start of the year, and you attach the election statement to a timely filed return. Without an audited financial statement the policy does not have to be in writing, though writing it down costs nothing. For the small, recurring purchases that never reach the Section 179 threshold, that safe harbor is the route the books should be using all year.
One caution on the afterlife of the deduction. If business use of the property drops to 50 percent or less at any point in its recovery period, you have to recapture part of the deduction as ordinary income on Form 4797. You do not pay back the whole thing. The recapture is the Section 179 deduction minus the ordinary depreciation you would have been allowed over the same years.
The December trap
The deduction follows the year the property is placed in service. The IRS defines that as the date it is ready and available for its specific use. Buying, ordering, and paying in a different year do not change the date. The IRS's own example is a machine delivered in one year but not installed and operational until the next. It is placed in service in the second year. You do not have to be using it. Ready and available is the test, and it leaves room for a delivered laptop on a shelf in the last week of December to count for 2026.
For a calendar-year business the 2026 tax year closes December 31, 2026. That is the deadline that matters. The return itself is due later: March 15, 2027 for S corporations and partnerships, April 15, 2027 for C corporations and Schedule C filers, computed from the IRS rule because the 2027 calendar is not out yet. No return deadline rescues equipment that was not in service by December 31. Ordering in December with a January delivery means a 2026 cash outflow on a 2027 property. It is the same December scramble the year-end books work is trying to prevent, only the stakes here are a purchase decision made in November.
Exhibit 2
A purchase made only to save tax spends a whole dollar to save a fraction of one.
A deduction saves you a fraction of the dollar you spend, and a purchase made only to save tax spends a whole dollar to save a fraction of one. If the item was not going to be bought, the result is a loss with a deduction attached, and the fraction saved does not pay back the whole dollar spent. The purchase you did need is worth making before the year ends, because the work pays for the cost and the deduction is a small extra on top. The cash leaves in December; the saving arrives later, as a smaller number on the return.
The test to run before the tax test
Before you sign the purchase order, run three checks. First, do you need it anyway? The equipment has to pay for itself in the work, on a timeline that is real and has nothing to do with the end of the tax year. Second, can you pay for it? Cash out in December is gone in December. The saving arrives as a smaller number on the return, and only up to the income limit, so a purchase that stretches the cash flow to reach the deadline is spending working capital on a fraction of a dollar. Third, can it be ready and available by December 31, 2026? Delivery, installation, and the moment it is usable all have to land in the year. If any answer is no, the purchase belongs in January, and the 2026 deduction does not exist.
Exhibit 3
Need, cash and a December 31 in-service date are the three tests, in that order.
States are not automatic
If you file state returns, the federal number does not travel. California caps its own Section 179 election at $25,000 with the phase-out starting at $200,000, does not conform to 100 percent bonus depreciation at all, and refuses the federal treatment of off-the-shelf software and qualified real property, so a California business can face three separate differences on one purchase. The FTB's published figures are the 2025 edition, so confirm them before filing. Florida goes the other way on bonus depreciation. A Florida corporate income tax filer has to add federal bonus depreciation back on Schedule I and then take one seventh of it back each year for seven years, and the add-back only reaches businesses that file the Florida corporate return. Because Florida has no personal income tax, a sole proprietor or single-member LLC is not affected. If your state is neither, the state treatment is a question for your CPA, and the answer can change which route, if any, is worth taking.
What the books have to hold
The deduction, the carryover, the recapture and the state add-back all run on the same small set of records: each item, who you bought it from, and when you placed it in service. For a December purchase the proof has to be in the year: the invoice, the delivery note, and a line in the books on the day the equipment was ready and available. Whether your accounting software holds that trail cleanly is one of the things to weigh when choosing between QuickBooks, Xero and Wave.
The part of this we take on runs all year. We keep the books close enough that December is a review, and that the taxable-income number the Section 179 test depends on is something you can state before you sign the purchase order. The work is described at our bookkeeping service.