Microsoft on Wednesday sent out word that it will "retire" its Messenger online chat feature on March 15 and replace it with the Skype Internet telephony service it bought last year.
Microsoft sent an email message advising Messenger users to update to Skype using their same account information in advance of the deadline.
"You'll be able to instant message and video chat...just like before, and also discover new ways of staying in touch with Skype on your mobile and tablet," Microsoft said in the message.
The Redmond, Washington-based technology giant announced in November that it was shutting down Messenger in favor of merging users into Skype.
The transition began late last year with the release of Skype 6.0 software that lets people sign in to the online communication service using Microsoft accounts. Messenger will be shut off in every country but China.
Skype features include video calls and being able to call mobile phones from computers, as well as being able to connect with friends at leading social network Facebook.
A Skype feature on Facebook, a social network in which Microsoft owns a small stake, allows for multi-person conversations and instant one-on-one video calls with friends.
Skype users can make low-cost or free phone calls over the Internet using their computers or smartphones. Skype bypasses the standard telephone network by channeling voice and video calls over the Web.
Microsoft bought Skype for $8.5 billion in 2011.