Unless you indicate that you want to attend court and provided you plead guilty, your case will initially be heard under the “Single Justice” (SJ) procedure at a hearing which you cannot attend.
If the SJ believes that points are appropriate you will be sentenced by that court and informed of the outcome by post. Only if the SJ believes that a ban should be considered will your case be adjourned to a hearing in the normal Magistrates’ Court and you will be asked to attend.
As above, six points is the most likely outcome.
They recently changed that road from 30 to 20 and my fault for forgetting about that….
Also, your fault for forgetting that 42mph is considerably in excess of 30mph and would have seen enforcement as well.