I want to buy a phone but on the already existing subscription, I don't want to get another SIM and

[Alexandra28]

• I want to buy a phone but on the already existing subscription, I don't want to get another SIM and another plan

[Anonymous]

Go to Argos. 

[sc1999]

Talk to customer services about an upgrade. If you upgrade you will not get another sim or number but may not be able to keep your current plan. You could always buy a new phone and use your existing sim and plan.