I am often asked how to add a Skype contact to Lync so I thought I’d do a quick write-up.
The important thing to remember is that the Skype user must use a Microsoft Account ID (eg firstname.lastname@example.org) to log into Skype; Skype names cannot be included in the Lync client. Additionally, your Lync platform must be configured for Federation with the Skype platform. Your user account must have an External Access policy that allows you to federate with Public Users.
Once this is all in place and you have the Microsoft Account ID that you want to add, you can just type this into the client and then right click the contact and select add to contacts.
Alternatively, you can click on the “Add a contact” button (circled in the screen shot below) and then select “Add a contact not in my organisation” then select “Skype”.
You then just need to enter the Skype user’s Microsoft Account ID in the “IM Address” field, select a contact group (if required) and the Privacy Relationship in the resulting dialog (below) and click OK.
The user will appear in the group you selected and you will be able to interact with then directly from your Lync client when they are online. The contact is easily identifiable as a Skype user.
I hope this helps!