A verification code is being sent to an old phone number of mine. I no longer have the phone but is there a way I can access this to get the verification code for example getting a replacement SIM card for that number?
Can you expand a little on what you mean by "an old phone number"?
If this was a pay-monthly number that has been disconnected, then it has indeed been lost.
If this was a PAYG number, then if it was used in the last 272 days you may have a chance of recovering it. Take a read of the EE hibernation policy which explains this further.
