When a member transfers their number into giffgaff, put a temporary divert (or announcement) onto the old giffgaff number.
I've been a giffgaff member for several years, but I didn't get rid of my old number on a different network. I kept both numbers going while comparing the coverage, and now my friends know both numbers, although the number on the other network is the one I want to keep as it is more memorable.
I can easily get a PAC and transfer the number into giffgaff, but that will immediately disable the existing giffgaff number that I've been using. I would like to be able to put an announcement or a divert onto the number for a month or two, while it is the recycling process which normally lasts for 6 months. Ideally I'd like to also put an announcement reply on to the SMS text service too.
I don't know whether this is technically possible, and it might need to be implemented by the third-party company that handles the transfers, rather than by giffgaff.
If the system requires calls to dead numbers to be seen by the caller as dead, perhaps I could receive a daily summary list of numbers that have tried to call or text to it? That way I will know who has ignored my requests for them to update their contacts list.
I'd be happy to pay for the diversion costs, if it can come from the unlimited minutes and unlimited texts on my goodybag.
If giffgaff implemented this idea, or could persuade the other company to implement it, existing members would feel more confident about transferring all their services from other networks to giffgaff. It might also be possible to use this method to help deal with problems that sometimes arise during a number transfer - telling the caller that there is a problem, and suggesting an alternative temporary way to make contact.