How to add another O2 mobile number to my account

[Nitz]

I need to add another O2 number so I can track the usage. 

Can't find any link under my O2 to add this other number. 

Thanks. 

[jonsie · Accepted solution]

At the moment O2 have withdrawn the merging of accounts while changing everyone to a new billing system

Whether this is reintroduced in the future is anyone's guess

In the meantime you need a seperate email address and register another My O2