If you are logged in to the same Skype account on two PCs at the same time and receive an incoming call, both of the computers will ring and prompt you to connect. However, you can only connect to the call on one of the computers, so if you accept the call on one computer the other will stop ringing.

Skype Incoming Calls

Skype is designed to work across multiple types of devices at the same time. For example, you may run the program on your phone, tablet, work laptop and home desktop: you can be signed in to the same account on all devices at the same time. Since the goal of the call is to reach you wherever you are, all of the devices logged in to the service will ring at the same time: the program does not use an "active system" selector, sign out the previously signed-in device or block additional sign-ins when operating with multiple devices.

Multiple Device Calling

While the initial call will ring on every device connected to the account, only the first device to answer the call will be able to participate. You can't initiate a three-way call on Skype using only two accounts: each participant needs an individual account.