@NerdyDad said in Yealink DECT dongle for T41S and T42S:

Does the cordless and the deskphone both share the same extension? If so, this would be great for my wandering receptionist.

These are independent units so no. But you can put the same ext on them if the PBX supports it.

So with FreePBX and PJSIP based extensions you can have multiple devices registered all to the same ext.