10% +2 is the starting point for enforcement unfortunately so in a 20mph limit that is 24mph. And it isn't something to rely upon as it is guidance. Having said that I don't have solid evidence of enforcement starting at lower thresholds despite ex son-in-law telling me he got done for 32 in a 30.
That speed should qualify for a course unless one has been done in the last three years. About 2 - 3 hours and £90 or so, no points.
At present the request is only for the drivers details and there is no point in delaying providing these. Failure to reply in time will be very costly incurring 6 points and, iirc, a £300 fine.
