From Publication 551, "Basis of Assets" "The basis of an intangible asset is usually the cost to buy or create it." They don't mention software specifically,

From Publication 551, "Basis of Assets" "The basis of an intangible asset is usually the cost to buy or create it." They don't mention software specifically, but they say that for patents and copyrights you can only include costs you actually paid for, and you specifically may not include the value of your own time spent inventing or authoring. https://www.irs.gov/publications/p551/ar02.html#en_US_201412_publink1000256923 https://www.irs.gov/publications/p551/ar02.html#en_US_201412...