Call Forwarding set to 3 different numbers (unrecognisable numbers)

[Kotuwi]

When I set up my phone to text alert and go into the call forward settings. I've seen three different numbers that I don't recognise that may belong to O2 text alert/voicemail services.

Always Forward - Off

When Busy - +4478020...6

When unanswered - +4478020...0

When unreachable - +4478020...7

I've also seen the number +4478020...1 for all three call forward settings as well.

Calling these numbers with my phone just leads to a dead-end but I haven't tried calling from a different phone.

Are these numbers automatically setup by O2? I have not input these numbers in myself.

[madasaf1sh]

@Kotuwi 

Without knowing the rest of the numbers it is impossible to tell, but the first part of the number is the original o2 dialing code 0802 (which is now 07802 ) 

Phone text alert is done by the service so wouldnt show on your phone.

[Kotuwi]

Searching up some of these numbers don't really show much on search engines. Just some negative ratings on whocalledme based websites.

If it helps: I recently joined O2 (new phone/simcard) but retained my old number.

[MI5]

@Kotuwi Call forwarding would normally be set to your voicemail number (901 for O2)

Guide here Guide: All you need to know about O2 Voicemail 901 

[Kotuwi]

I think I deactivated 901 O2 voicemai when I activated O2 Call Alert.

I followed the guide earlier by dialing 1710 but haven't used the ## 002 # function.

*#21# SEND shows Voice: Not forwarded

*#61# SEND shows Voice: +4478020.. after 15 seconds