O2 is the second oldest mobile network operator in the UK, launching way back in 1985 under the name of Cellnet. The network rebranded as O2 in 2001 and has been operating under the same name since then. With over 34 million customers, O2 is the second-largest UK mobile network operator, behind only EE.
The mobile network offers pay monthly deals, as well as PAYG alternatives, but you can’t use the service on a traditional PAYG basis. O2 provides 5G services to its customers, just like all the other major networks. The carrier’s most unique offer is allowing you to build your own custom plan when buying a handset from the O2 Store. You may choose how much you wish to pay upfront, the length of contract (from 3 months to 36 months) and the amount of data you’ll have in your price plan.