Unlike the old days where your phone number was enough, Facebook Messenger now requires a Facebook account to sign up, reports VentureBeat.
The social networking giant has quietly removed the ability to sign up for Messenger without a Facebook account.
"If you're new to Messenger, you'll notice that you need a Facebook account to chat with friends and close connections," a Facebook spokesperson was quoted as saying in the report on Thursday.
"We found that the vast majority of people who use Messenger already log in through Facebook and we want to simplify the process. If you already use Messenger without a Facebook account, no need to do anything," the spokesperson added.
However, some Messenger users without Facebook accounts reported they received an error message while trying to login with their phone numbers.
This move appears to be the big aim of providing an integrated, unified experience across Facebook family of apps - WhatsApp, Messenger and Instagram.
"People should be able to use any of our apps to reach their friends, and they should be able to communicate across networks easily and securely," Facebook CEO Mark Zuckerberg said recently.
"We plan to start by making it possible for you to send messages to your contacts using any of our services, and then to extend that interoperability to SMS too."
Nearly 1.3 billion people use Facebook Messenger each month.
( With inputs from IANS )