From the Home Office guidance I got and impression, that online printouts are acceptable, if tax return is done online rather than by post.
This is what they write:
copy or
printout of your most recent self-assessment tax return (SA100) and evidence that it has been received by HMRC (e.g. written notification
or printout of online confirmation)
copy of form CWF1
or printout of their online registration as a self-employed person with HMRC evidence that HMRC has received their application – e.g. letter
or printout of online acknowledgement
At the moment we cannot call HMRC and order anything by post from them, for the reason that my husband's English is not too good and he is not confident enough to speak to them
In the past I spoke to HMRC on his behalf, when I was with him in UK. Now I am not in UK. Also, that's why he is using an accountant that speaks in his native language, and the accountant is on holiday until September.
Will they really not accept online printouts? If not, why they write about it as an alternative form of proof?