Does Skype for Business Online work with Exchange 2013 On prem?

[Ash Chaudhury]

A partner of mine has a customer with Exchange 2013 on Premise and is looking to purchase Skype for Business either plan 1 or plan 2. How will Skype for Business work with Exchange, Outlook, if it all?  What are the requirements?  Do they need AD Connect setup

[#2]

It depends on what components you want to use.
If you provision users (regardless of method) in Skype for Business Online and they have the Skype for Business client installed, as long as the SMTP address matches the SIP address then presence will work within the Outlook client.
The table on this page shows the feature support between various platforms, such as Exchange Server 2013 and Skype for Business Online: https://technet.microsoft.com/en-us/library/ea22beb9-c02e-47cb-836d-97a556969052#feature_support

[#3 · Accepted solution]

And here's detailed guidance on the steps you need to follow for the different features: https://support.microsoft.com/en-us/help/2614242/