I currently have 9 points on my license. Of which the first 3 points are now over 3 years old - so I believe this means I technically have 6 valid points?

I got flashed on the M25 last nite by an overhead camera just as you approach the variable speed limit area for the M4 (anticlock wise) doing around 85 - 87 mph. I've been passed that stretch of road loads of times and never known that camera to go off - didnt actually know there was one there!

Anyways, I expect it will have been loaded with film and I'll expect to get a nice letter in the post in the next few weeks so my question is:

Am I now liable for a ban? Or as my first 3 points are over 3 years old I'll just go back to 9 valid points?

all my points so far have been SP30s, (I think this particular offence is an SP50?)