Changing a SIP Address in Lync or Skype for Business
What happens when you change a user's SIP address in Lync 2013 or Skype for Business?
I was being asked about changing a SIP address for a user today on Lync 2013 - equally applies to Skype for Business too. What would the effect be on Contact lists? Say for example your login was 'DerekT@TheForce.co.uk', and that's what you were on people's contact lists as … What would happen if you changed that SIP login to 'Derek.Trotter@Deathstar.co.uk'?
Well, the answer fortunately is a positive one. It works. The contact subscriptions are held in the database by a unique identifier created at the time of subscription - this unique ID is not the SIP address. So, change the address, and when people with that user on their contacts list logs out of Lync/Skype and back in, they'll still see the person on the contact list with presence and everything.
One thing I've found by the way is that if you change the domain - I.e. The bit after the @ - you can see issues with authentication to Lync/Skype. Easily fixed by logging the user out/in again.
So you can change these addresses. You do need to plan when you change them though - may also be worth deleting and updating the address book files too. Now, this works well enough for contact lists - but one thing you must educate your users is about is that scheduled meetings will break. Users with changed SIP addresses should go back and re-send any meetings they have in their diary, so that they contain the right URLs for the conferences - otherwise the conference joins will fail.
Anyways, the video here shows the behaviour in action.