It is regulated.
As the regulator describes it “Phone payment is a popular and easy way of paying for a range of content, goods and services, including music subscriptions, games, donations to charity and voting on TV talent shows”
The Phone-paid Services Authority website includes a checker and the contact details of the firm responsible for the short code.
this did cross my mind; the telecoms equivalent of banking’s “merchant data.” I’ve asked if they have an API available, otherwise we’ll have to start collecting our own data…