it appears on your license as an SP code. Mine shows SP50 for speeding on a motorway. Points colum is then "blank" and the ban colum has "28D" in it for the 28 days i got.
Ive previously been banned for doing 107 around midnight on an empty m1. Was caught by a patrol car parked up in the dark at the bottom of a long hill before J41. Attended halifax magistrates and got fined £70 and banned for 28 days.
If anybody (including insurance co's) ask if you've got any convictions, then yes you do. Only difference is that the offence carried a ban rather than points. a 6 point conviction and a tempoary ban conviction both effect the insurance about the same. Its not possible for me to give an exact figure, as i lost my NCB in a small bump the same year, but it adds around £300 to my current premium, driving a Group 18 Vectra VXR. Obviously if you drive a low IG car, this wont be the same.
And you're correct, there are problems with banning you when your not in court in that they need to take your license to do so. You could get around the process by filling in the form indicating you wont attend, and then sorting it out afterwards at a secondary hearing.
Problem is with this method though, is they will likely throw the book at you. Magistrates take it that if you dont attend, you dont consider the offence serious enough to turn up. In this case, they will usually make sure they given you a punishment that makes you realise your actions.
Fundamentally if your not bothered about the fine, the worst they can do is 56 day ban and this is very unlikely. Somebody on here got caught doing 116 on the motorway and still only got 28 days. So they will most likely fine you more.
Its a maximum £1000 but its means tested so they cant fine you an ammount you'll never pay. If your short on cash, considering attending to keep the fine down. If your not bothered, then just dont appear and let them decide how much.