Section 1231 is the Internal Revenue Code provision that decides whether gains and losses on property used in a trade or business, and on involuntary conversions of that property or of a capital asset held for more than 1 year in connection with a trade or business or a transaction entered into for profit, are capital or ordinary, and it decides that for the whole tax year rather than asset by asset (26 U.S.C. 1231(a)(3)). Combine every section 1231 gain and loss for the year: a net loss is ordinary loss, and a net gain is ordinary income up to any nonrecaptured section 1231 losses from previous years, meaning net section 1231 losses from the previous 5 years that have not been applied against a net section 1231 gain, with the rest long-term capital gain (IRS, Publication 544 (2025)).
What Qualifies as Section 1231 Property
The class is narrower than business property. Property used in the trade or business means property used in the trade or business, of a character which is subject to the allowance for depreciation provided in section 167, held for more than 1 year, and real property used in the trade or business, held for more than 1 year (26 U.S.C. 1231(b)(1)).
Four classes come straight back out. Inventory goes first, meaning property of a kind which would properly be includible in the inventory of the taxpayer if on hand at the close of the taxable year, and with it property held primarily for sale to customers in the ordinary course of the taxpayer’s trade or business. Work product goes next, covering a patent, invention, secret formula, copyright, composition, letter or memorandum, and the exclusion turns on who holds it: whoever created it by personal effort, whoever a letter or memorandum was prepared or produced for, or anyone whose basis in the property is determined by reference to a holder of either kind (26 U.S.C. 1221(a)(3)). Last is a United States Government publication received other than by purchase at the price offered to the public and held by a taxpayer described in section 1221(a)(5) (26 U.S.C. 1231(b)(1)(A) to (D)). Outside the statute’s own list, property whose cost was deducted under the de minimis safe harbor for tangible property is not treated as property used in the trade or business under section 1231 either, so gain on its disposition is generally ordinary income reported in Part II of Form 4797 (IRS, Publication 544 (2025)).
The holding period is load bearing. Depreciable business property held for a year or less never enters the definition, so its gain or loss never reaches the netting. Why that property is also outside the capital asset definition, and what the full section 1221 exclusion list says, is set out in capital assets.
The Categories the Statute Names Separately
Three groups are written into the definition by name, and they decide the character of a disposition for farm, ranch and timber clients. Timber, coal and iron ore with respect to which section 631 applies are inside the term (26 U.S.C. 1231(b)(2)).
Livestock carries two holding periods rather than one. Cattle and horses, regardless of age, held for draft, breeding, dairy or sporting purposes qualify at 24 months or more from the date of acquisition, other livestock held for those same purposes qualify at 12 months or more, and the term does not include poultry. An unharvested crop on land used in the trade or business and held for more than 1 year is treated as property used in the trade or business when the crop and the land are sold, exchanged or involuntarily converted at the same time and to the same person (26 U.S.C. 1231(b)(3) and (b)(4)).
Involuntary Conversions Arrive Under the Same Section
Involuntary conversions are the other half of the section’s title, and the statute brings them in on its own terms. Section 1231 gain includes any recognized gain from the compulsory or involuntary conversion of property used in the trade or business, or of a capital asset held for more than 1 year in connection with a trade or business or a transaction entered into for profit, where the conversion follows destruction in whole or in part, theft or seizure, or an exercise of the power of requisition or condemnation or the threat or imminence of one (26 U.S.C. 1231(a)(3)(A)(ii)).
Casualty and theft conversions get a rule running the other way. Where such a conversion arises from fire, storm, shipwreck or other casualty, or from theft, the subsection does not apply to it at all, gain or loss alike, if the recognized losses from such conversions exceed the recognized gains from them during the taxable year (26 U.S.C. 1231(a)(4)(C)). A bad casualty year is walled off from the netting instead of dragging the column down with it.
Net Gain Is Capital, Net Loss Is Ordinary
The netting runs on the whole year’s section 1231 column, and on the part of each gain left after recapture rather than on the whole gain.
Section 1231 gain on a truck, after recapture 12,000
Section 1231 loss on a warehouse (20,000)
Losses exceed the gains, so neither side is capital
Net ordinary loss 8,000Reverse the two sides so the gains are larger and both become long-term capital instead, the truck gain a long-term capital gain and the warehouse loss a long-term capital loss (26 U.S.C. 1231(a)(1)). Nothing about either asset changed, only the year.
A lookback sits on top of a net gain. Net section 1231 gain is treated as ordinary income to the extent it does not exceed the non-recaptured net section 1231 losses (26 U.S.C. 1231(c)(1)). Non-recaptured net section 1231 losses are the excess of the aggregate amount of the net section 1231 losses for the 5 most recent preceding taxable years over the portion of those losses already taken into account under that rule in those preceding years (26 U.S.C. 1231(c)(2)), and they are applied against the net section 1231 gain beginning with the earliest loss in the 5-year period (IRS, Publication 544 (2025)).
What Is the Difference Between 1231 and 1245 Property?
They are not alternatives, and one asset is routinely both. Section 1245 recharacterizes part of a gain and section 1231 characterizes whatever is left. On a gain from a section 1231 transaction, first determine whether any of it is ordinary income under the depreciation recapture rules and do not take that part into account as section 1231 gain, because only gain in excess of the recapture amount is section 1231 gain. A depreciated machine held longer than a year sits in both places at once: the depreciation slice is ordinary income and any gain recognized above it is section 1231 gain (IRS, Publication 544 (2025)). How that ordinary slice is computed, and where section 1250 changes the answer for real property, is depreciation recapture.
Where Do You Report Section 1231 Gain?
On Form 4797, Sales of Business Property. Part I takes the section 1231 transactions that are not required to be reported in Part III, and where the Part I amount is a gain and there were no nonrecaptured section 1231 losses from prior years, that gain is entered as a long-term capital gain on the Schedule D for the return being filed (IRS, Instructions for Form 4797 (2025)). Where there are nonrecaptured net section 1231 losses from prior years, they go on line 8 and line 9 subtracts them from line 7: if line 9 is zero, the gain from line 7 goes on line 12 in Part II, Ordinary Gains and Losses, and if line 9 is more than zero, the line 8 amount goes on line 12 and the gain on line 9 is entered as a long-term capital gain on the Schedule D filed with the return (IRS, Form 4797 (2025)).
Section 1231 gain or loss from a like-kind exchange on Form 8824 is carried into that same Part I (IRS, Form 4797 (2025)), so the like-kind exchange rules settle how much gain is recognized while this section settles what the recognized part is.
A firm that wants disposition workpapers and the section 1231 column prepared and reviewed before anything client facing depends on them can put a real block of that work through a trial task.
