Question: do you have to file a federal estate tax return?
Answer: To send an estate tax return, you must first register the estate online. You must register by 5 October after the tax year you're sending a return for. For example, if you're sending a return for the 2019 to 2020 tax year (6 April 2019 to 5 April 2020) then you must register by 5 October 2020.