SpaceX founder Elon Musk confirmed this week that its satellite broadband subsidiary Starlink will provide mobile phone Internet in the US exclusively to T-Mobile for just one year.

From then on, the service will be opened up to other mobile carriers, he added in a post on X (formerly Twitter) earlier this week.

"Starlink direct to mobile phone Internet is exclusively with T-Mobile in the US for the first year, then other carriers thereafter," posted Musk. "We are starting off working with one carrier in each country, but ultimately hope to serve all carriers."

Musk made the comments in reply to a post from SpaceX senior director of satellite engineering Ben Longmier, who was outlining the company's direct-to-cell program, which recently added 26 satellites into Low Earth Orbit (LEO) via a pair of Falcon F9 rockets last month.

He added that the company now has 168 compatible Starlink satellites in orbit.

T-Mobile and SpaceX first announced their partnership in August 2022, as the carrier set out plans to provide mobile signal connectivity from space with the target of leaving no area without coverage in the US.

It's expected that T-Mobile will use its mid-band spectrum (likely 5G) to connect devices with Starlink’s satellites.

Details about the pricing of the service have yet to be confirmed by either company.

Last month, T-Mobile's domestic rivals AT&T and Verizon told the Federal Communications Commission (FCC) to delay T-Mobile and Starlink's planned direct-to-cell satellite service, claiming that the plans will harm their respective mobile broadband networks.

SpaceX said its proposed SCS operations will not harm its competitors, while the company along with T-Mobile has claimed the filings are a tactic to delay its deployment of the service.

AT&T and Verizon have their own partnerships with AST SpaceMobile to provide 100 percent coverage across North America through messaging services.