Can i ask for a port code to change mobile networks and then not use it? ?

i'm thinking of changing networks from O2 to Vodafone, i'm not sure how great my credit rating is at the moment though so i'm not sure if i'll be accepted. i'm going to see if i can order online but would like to keep my mobile number.



Does anyone know if i ask for a PUK code now can and i don't get accepted can i just carry on using my current phone?Can i ask for a port code to change mobile networks and then not use it? ?
YES.



they expire after 30 days of being granted (and not sometimes when they arrive in the post a week later).



doing this alos prompts your existing carrier into offering you their leaving deals!!