Yes, sorry lol. I believe you only get a NiNo on the back of yours if you have a BRP for a tier visa or something like that. Those who have spousal visas do not get it on the back of their BRP from all that I've read. I have a spousal visa.
That would make sense. An immigraion officer said on another site that HMRC do regular sweeps for UKVI to make sure people are not in breach of their visa conditions for work. i.e. are paid at the same rate as their CoS, not working for another employer instead of the one that sponsored them, not self employed, not trying to work for two employers on a student visa and double the time they are allowed to work etc.
HMRC had a new system called Real Time brought in during the 13/14 tax year and that seems to have caught a few out, not only those on PBS visas but also those on income based welfare payments i.e. Tax Credits.
If a visa is curtailed, UKVI can trace where they are working through their NI and inform their employer that they have no right to work. Employer then terminates their employment. It will be interesting to see if they do bring this in for a spouse visa too, in case they lose their sponsor but try to stay on in the UK.
Anyway, UKVI arranging NHS numbers and NINos, is good new for those who don't intend to break the laws.