Does a closing of a house on 1/4/2021 count towards 2020 or 2021 taxes? I know the cutoff for the stimulus check is 1/15/2021 so was wondering if it was the same idea.

[Miss MCJ2]

It will be reported on the 2021 tax return.  The stimulus check cutoff is a special effort to try to get as many checks paid out before people start to file the 2020 taxes.

[xmasbaby0]

Not sure what you are trying or hoping to enter in regard to closing on a house.  Buying a house in itself is not something to report on a tax return.  What you enter about home ownership---for the tax year in which you ARE a homeowner-- is mortgage interest paid, property tax paid, private mortgage insurance paid, and loan origination fees ("points").    At the end of a tax year in which you have owned a home, you get a document called a 1098 from the lender that you use on your tax return if you are itemizing deductions.  

But since you say you are buying /selling a house in 2021, you have nothing about that to enter on a 2020 tax return.  Wait for next year.