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

https://wiki-square.win/index.php/What_Are_the_Most_Common_Reasons_a_Mobile_Casino_Deposit_Gets_Declined%3F

UK players have moved from using phone bill deposits, which often had limits like £30 per transaction, to Faster Payments and mobile wallets. These modern methods let you deposit as little as £10 instantly