O2 Sim Only O2 Sim Only deal is known as Simplicity. Just like the name itself, it is simple to get subscribed to the plan. If you have been an existing O2 user, you can change to Simplicity via this site. If you are a new user, you can register online.

Or if you want to keep using your old phone but do not want to get a new phone to subscribe to the call plan, an O2 Sim Only deal is the way to go.

Simplicity is also the only O2 Sim plan they are offering at the moment. By subscribing to Simplicity, you get the same value as a 18-month contract but you pay less for that. Even though there isn’t many O2 Sim Only deals but having one is more than enough when the benefits are greater than any other plans.