EE SIM Only
Formed from the merger of Orange and T-Mobile, EE has fast become a force to be reckoned with in the UK mobile market. EE were the first network to launch 4G and have built one of the biggest and fastest 4G networks in Europe and are the only network to offer double-speed 4G.
EE has revamped their SIM plans recently to accommodate 5G and increase data allowances. Though you're likely to find more allowances with Three or Tesco Mobile (who run on O2's network) you do get a full range of added extras with EE.