In reply to yorkshire_lad2:
I remembered the trouble I had trying to get a covid test last year. Same problem of data not recognised. I now remember that the final step was to use a credit reference agency to 'validate identity'. Therefore those who don't have credit don't exist. I suspect this is the same problem, since it's obviously using the same identity interface.
From googling, it looks like the opt out deadline has been put back to August 23, but there's no mention of that (or, in fact, any deadline) on the opt-out website.
All nice and transparent, eh? Really inspires trust.
Oh, and David: you obviously missed the very long thread about opt out, so I'm not going to repeat that argument again.