Road Traffic law is the same either side of the border.
A straight no insurance, provided there are no other offences disclosed, may be dealt with by a conditional offer of fixed penalty of £200 and 6 points. It is exactly the same as a speeding offence which carries 3 points and a £60. There are a numberof other fixed penalty offences that can, but are rarely used, such as failing to comply with the requirements of Section 172 of the RTA 1988.
It is rarely used however, as you very rarely have a straight no insurance offence. There's usually a licence offence or a cause/permit offence which are usually reported together as a summons.
It is not a conviction, as you have not been to court and convicted of the offence.
A foolish, but not a serious offence, and certainly not one that will affect a career. Unless you're a cop that is...