Not sure if theres a systematic way... a while ago you could kind of tell what numbers belonged to which network (Orange was usually 0784... or something I cant remember) but since then people have changed networks a lot and kept their old numbers. Hmmmmmmm......
You can tell orange number by the fact they give one long ring at the start, But sadly thats not diagnostic any more because 3 phones using the 2G orange network do this too. Boo Hoo. If you call it and it goes to voicemail though, and if you've called enough voicemails to know, you can tell which network it is from the sound of the woman who does it.
(Original post by wesetters)
I don't know if this works in the UK, but here you can tell from the beginning or the number - for example, my phone number starts 066, which means it's on the bouygues telecom network.
nah that doesn't work here, all mobile numbers begin with 07and then have 3 other numbers, but the same network can have 3 different numbers there so it's impossible to tell who's on one network alone let alone compare them all.
As has beenn said - it was possible to get it pretty much right before people coudl easily port their nubmers around - now its near impossible as someone on here has demonstrated by moving their number aorund a lot.
The Orange thing does work tho because they have one logn ring followed by standard shorter ones.