Let us help you cancel your O2 contract
Follow this guide to cancel O2.
Who are O2
Telefonica UK Limited (known as O2) is a telecommunications services provider in the UK, owned by Spanish multination Telefonica. With over 25 million subscribers (as of May 2017) O2 is the second-largest mobile telecommunications provider in the UK.
How to cancel O2 myself
1) Find out when your contact ends by navigating to this site.
2) If you want to end your contract but keep your number, you will need to contact O2 and receive a PAC code, to give to your new provider. The PAC code is valid for 30 days. Your account will close once the PAC code is used. Until the PAC code is used, you will still be charged.
You can contact O2 by navigating to this site.