It is; the UK has very strict KYC laws and any institution handling money is quickly on the hook for certain misdeeds by their customers. They need to show diligence in monitoring that activity.

> You must meet certain day-to-day responsibilities if your business is covered by the Money Laundering Regulations. These include carrying out ‘customer due diligence’ measures to check that your customers are who they say they are, and risk assessing your business.

https://www.gov.uk/guidance/money-laundering-regulations-you...

(That entire page, like the rest of gov.uk, is comprehensive and very accessible to read for a layman. If you have any passing interest in the area I recommend giving it a skim.)

In hindsight, I probably should have switched banks, but ~~15+ years ago~~ I was young enough that it mattered very little to my sense of principle.

They've otherwise been quite reliable since so jumping ship now would almost be asking for trouble.

Edit: It wasnt 15 years ago this happened, it was perhaps a decade. I'd already been a customer for some time.