I am using HMRC's own Tax Return software on my few remaining cases. ( It was fine last year!) The self employed case I am doing currently claimed some SEISS which is correctly entered in the Self Employment section of the form.
However, I am unable to engineer a cross in the new box 20.1 to confirm that all Covid Support has been reported. I would have expected to have been asked to confirm this at the end of the input process - but I wasn't so asked.
Just wondering how commercial software deals with this?