Can I add all the property taxes since then to the cost basis of the land?
Assuming we're still talking about 2017 taxes, and assuming you sold the property in 2017, yes you can. However, you must subtract from that amount, the amount the buyer reimbursed you for, as the buyer would get credit for paying the property taxes prorated, based on the date of the sale.
Otherwise, if you did not sell the land in 2017 and still owned it through 2020, the property taxes are carrying costs that won't come into play until the tax year you do sell it.
@M-MTax is that right? Since the property has been raw land since the demolition in 2017, I would assume any sale would be reported in the investments section of the program.
