UK players have moved from using phone bill deposits, which often had limits...

https://trentontmkn327.lucialpiazzale.com/why-did-phone-bill-deposits-have-such-low-limits-in-the-uk

UK players have moved from using phone bill deposits, which often had limits like £30 per transaction, to faster, more convenient options. Modern methods like Faster Payments allow deposits as low as £10, clearing almost instantly