Microsoft today announced that it has completed the first step towards pervasive interoperability between Skype and Lync. In this initial stage, the firm has enabled contact federation and audio calling and instant messaging between the two services.

“We are thrilled to announce the availability of Lync-Skype connectivity,” Microsoft director BJ Haberkorn writes in a post to the Lync Team Blog today. “This marks our first important step in extending Lync’s unified communications capabilities to the hundreds of millions of people who use Skype. This combination enables Lync customers to take advantage of the global reach of Skype to connect and collaborate with suppliers, customers, and partners while relying on the enterprise richness of Lync.”

As you probably know, Skype is Microsoft’s semi-autonomous consumer-oriented communications service, which the firm is busy integrating into every viable product imaginable, including Windows 8, Windows Phone, Office, and Xbox One. Lync, meanwhile, is Microsoft’s corporate communications services, a sort of business-oriented alternative to Skype.

In February, Microsoft announced it would connect the services so that Skype and Lync users could interoperate across both. I wrote about this in Hey, You Got Your Skype in My Lync. This combination will happen over several stages through the first half of 2014, and today’s updates represent the first step.

And it goes both ways, so to speak. “With Lync-Skype connectivity, Skype users will now be able to reach a broader network of colleagues, partners and customers who are using Lync, Microsoft’s unified communications platform, connecting them into organizations of all sizes,” Giovanni Mezgec writes in a post to Skype’s Big Blog. “Lync provides a consistent, single client experience for presence, instant messaging, voice, video and meetings for business productivity and is owned by over 90 of the Fortune Global 100 companies.”

To connect to Lync from Skype, you must first sign in with a Microsoft account. Then, you can add your Lync-based contacts by using their email address to search and find them. Once they’ve accepted your contact request, you can instant message and audio call with them. (Video is coming in a future update.)

To connect to Skype from Lync, administrators will need to first enable this connectivity. For For Lync Online in Office 365, this happens through the Lync admin center. (And if you’ve already enabled Windows Live Messenger federation, you’re already all set.) If you’re using Lync on-prem, check out these instructions. Then, users with the Lync 2010 or 2013 client can add Skype contacts by searching for their Microsoft account via Add a Contact, Add a Contact Not in My Organization, Skype:

Good stuff.