In the September 28 communication, Julien Codorniou, the head of Workplace by Facebook, assured Clay Johnson, the enterprise chief information officer of Walmart, that steps were being taken to further separate Facebook's enterprise business from its consumer services. Facebook told the company it was soon giving the Workplace by Facebook service its own web domain, according to Walmart vice president Joe Park.

Walmart is a customer of Workplace by Facebook, a work version of the social network that companies pay for so their employees can communicate using Facebook-style features, such as private messaging, news feed posts and live streams. The service, which competes with Slack and other enterprise communications services, is used by 30,000 organizations, including Starbucks and Chevron, according to the most recent figures Facebook shared in October 2017 .

On September 28, the day that Facebook disclosed a security breach impacting millions of its users, the head of the company's upstart enterprise business reached out to Walmart , a top customer, to assure it that its data had not been exposed.

"The assurances we got were that data resides outside the consumer version of Facebook, and it's starting from the top to bottom, where they'll even change the domain name to reflect that," Park said.

The new domain, Workplace.com, is now live as a marketing website. It is expected to go into use as a landing page for Workplace by Facebook customers sometime in 2019, Luke Taylor, product manager for Workplace by Facebook, told CNBC on Wednesday.

The domain change comes as some Workplace by Facebook customers have previously expressed concern about the fact that the enterprise tool is hosted on the same domain as Facebook's consumer business, Taylor said. The company has been informing clients about the domain shift one-on-one.

"We have been in a position where even though we are separate from them, it's a bit difficult to have that story when we are hosted on the Facebook.com domain," Taylor told CNBC. "This is something that we want to do from a brand point of view but also something that I think gives our customers more trust in the product itself."

The company expects to start using the domain with new customers at first and then help existing clients migrate over, Taylor said.

"We'll be working with our customers to make sure that they migrate at a pace that makes sense for them," Taylor said.

"When you look at the Oculuses, Instagrams and even the Facebooks of the world, they all have their own domains and their own brand identity," Taylor said. "As we've seen our growth increase so rapidly and our traction in the market increase, we just felt it was exactly the right time to step forward with our own brand."

A Facebook spokesperson noted that "this move has been in the works for nearly a year."