Adding second mobile number to "My O2"

[Ant21]

Back again with another conundrum!  I have two O2 PAYG numbers that I use for different purposes.  One is registered to "My O2", and I have just been trying to add the second number.  I click the "Add products and services" link, enter the other mobile number as directed and then click the "Text me a code" button.  However a message then comes up "Identity not found", no text is received and I am unable to complete the process.  The other mobile number IS active and happily receiving texts and calls from other sources, so I don't understand the problem.       

[MI5 · Accepted solution]

@Ant21 

You can only add a PAYG number to a MyO2 with an attached pay monthly account.

Two PAYG accounts cannot be combined unfortunately.

[Bumblebox]

Not only can you no longer link a PAYG number with another PAYG number, you also cannot link a PAYG number to a Pay Monthly number. Only Pay Monthly numbers can be linked now. You will have to have a separate MyO2 account for each PAYG number.