Just checked that guide on my PC @gmarkj
Good find. (never knew it existed!!)
If you have wifi calling enabled in My O2 you may get an error message. Disabling it will allow you to dial in those codes.
Nice to see all the troubleshooting here guys. 
@DaveC Sorry to hear you've been having trouble with this - have you made any progress since you last posted? Any luck with customer service?
→ COVID-19 support - Help and support from O2 during the lockdown
→ Access for You: Registration - Find out how to register for our Access for You service.
→ Just joined the community or thinking of registering? Check out this handy starter guide!
→ Have a query about your account? See if the My O2 how-to guide will help
If you'd like to take part, why not register?
Hey @DaveC , sorry to hear that, sounds frustrating. 
I'm not sure how much more could be done if you don't have the phone at hand, but I'm happy to check with our Gurus to see if they can help further in any way. I'll drop you a Private Message here on the forum shortly to get a few additional details.
→ COVID-19 support - Help and support from O2 during the lockdown
→ Access for You: Registration - Find out how to register for our Access for You service.
→ Just joined the community or thinking of registering? Check out this handy starter guide!
→ Have a query about your account? See if the My O2 how-to guide will help
If you'd like to take part, why not register?
