The decedent died 04/19/20.  No reportable income items until liquidating stock on 12/10/21.  No prior fiduciary returns were filed. 

Can the Executor take the position that the initial year was a fiscal year (04/19/20 to 03/31/21) and no return was required, such that the initial and final return is filed for the period 04/01/21 to 03/31/22, with K-1s to the beneficiaries for their 2022 tax year personal returns? 

Or does the fact that no prior return was filed lock the Executor into the calendar year for the initial year?  In that case, there would still be just one initial/final return, but it would be for the 2021 calendar year, such that the beneficiaries report it on their personal taxes in the 2021 tax year? 

I'm not real clear on the timing when an estate has been opened for more than a year and no fiduciary return has been filed.  I was taught the first fiduciary return sets the tax year (rather than the EIN request or anything else), but I'm not sure if that applies when nothing is filed in the first 12 + 4.5 months.  Thanks!