If I wish to amend my married joint returns for 2020 as married single after filing, do we both file 1040X returns or one 1040X and the other as a standard 1040?

[phillkauf]

Filed 1040 and have received refund already. Refiling will increase refund (odd I know but the unemployment and other factors work in our favor this time.)

[xmasbaby0]

Married filing separately  is usually the worst way to file.    You only have until May 17, 2021 to amend from a joint return to separate returns.   You are not permitted to switch to MFS after the filing deadline.  You will both have to amend and send in a 1040X for yourselves.

https://ttlc.intuit.com/questions/2895311-how-do-i-switch-from-filing-jointly-to-filing-separately

Stay aware of the rules for filing MFS----either you BOTH itemize or you both use standard deduction.    Each of you has to file the same way.   

[SweetieJean]

Please be sure you do this correctly, especially if you live in a Community Property State.

[AmyC]

If one of the factors is that one of you owes money and had your refund taken, instead of MFS, you would want to do an injured spouse. See File as injured spouse

@SweetieJean is right as usual, community property states are tricky and may well end up the same.

@xmasbaby0 is on target as always,  correct about MFS being harsh for most people. If you have rental income, kids, or retirement funds, you may find MFJ is better. You only have until the May 17 deadline. See also: IRS: Topic No. 308 Amended Returns - Internal Revenue Service