Thanks for your question
You can get the online calculation form the online services, but mortgage companies will still not accept this (even though its the online version of the SA302) so you will have to telephone HMRC and ask them to issue on.
Call them on 0845(NNN) NNN-NNNNand phone as soon after 8am today or as close to 4pm as possible today to get through to an officer. (oR the lines are then engaged)
Or as soon after 8am Mon to Fri or as close to 8pm Mon to Fri
No, so you phone HMRC and they will send it to you, and the one from the online services will not be accepted by the mortgage lender anyway. So you need to ask HMRC.