1231 Property is a category of property defined in section 1231 of the U.S. Internal Revenue Code. 1231 property includes depreciable property and real property (e.g. buildings and equipment) used in a trade or business and held for more than one year. Some types of livestock, coal, timber and domestic iron ore are also included. It does not include: inventory; property held for sale in the ordinary course of business; artistic creations held by their creator; or, government publications. 1231 Property is a category of property defined in section 1231 of the U.S. Internal Revenue Code. 1231 property includes depreciable property and real property (e.g. buildings and equipment) used in a trade or business and held for more than one year. Some types of livestock, coal, timber and domestic iron ore are also included. It does not include: inventory; property held for sale in the ordinary course of business; artistic creations held by their creator; or, government publications. The 1954 version of the Internal Revenue Code included section 1231 covering certain property held by a business. The original section covering this matter - namely, section 117(j) of the Internal Revenue Code of 1939 - was enacted in 1942. The law was originally conceived as a way to help the shipping industry during World War II.