High paying UK casino sites: In-depth reviews 1. Highest-paying slot game: 1429 Uncharted Seas at MrQ.Fastest payout online casino: Voodoo Dreams (via e-wallets such as Skrill or Neteller).Overall best payout online casino UK: Magic Red.Below are the casinos that stand out most in the specified categories: The UK online casinos listed above are the best around for having high payout rates and being awesome to the game at. Best payout online casinos UK: Our winners Looking at the casino's overall RTP figure is a good way to determine if they are a high payout iGaming site. Typically expressed as a percentage, the higher the RTP figure the better for iGaming fans. Standing for return to player, RTP is the percentage of all the money paid into the casino or specific game that the casino site pays out to players in winnings over time. KingdomAce - Casino RTP not made public, but the highest RTP game is 99.00%Īs you can see from this list Mr Vegas has the highest payout rate for a UK online casino with an RTP of over 98% What is RTP?.Hotstreak Slots – Casino RTP not made public, but the highest RTP game is 97.04%.