Starlink & T-Mobile US Achieve First Direct-to-Cell Texts via LEO Satellites

SpaceX's Starlink and T-Mobile US have marked a milestone by successfully sending and receiving direct text messages via LEO (Low Earth Orbit) satellites using unmodified, off-the-shelf mobile phones. The messages were transmitted through the first half-dozen Starlink Direct-to-Cell satellites launched on 2 January.

The "system works!" declaration from SpaceX came just two days after the test messages were sent. Importantly, these tests used standard mobile phones with no special modifications. This confirms that the new service can work with existing devices and telecommunications spectrum—critical for wide adoption.

T-Mobile US has been Starlink's U.S. partner since mid-2022 for this Direct-to-Cell project. The aim is to eventually offer SMS, voice, data, and Internet of Things (IoT) services via satellite to address areas without reliable cellular coverage.

A number of other operators around the world have signed or are exploring agreements with Starlink—for example, Rogers (Canada), Optus (Australia), One New Zealand, KDDI (Japan), Salt (Switzerland), and Entel (Chile & Peru). These partnerships suggest a global strategy for extending direct satellite-to-cell connectivity.

In the U.S., the plan is to expand from these initial texting trials to offer full Direct-to-Cell services in 2025, including voice, data and IoT. To do that, Starlink will need to launch more satellites (building out the constellation), secure regulatory approvals, and ensure interoperability with existing mobile network operator (MNO) infrastructure.

Starlink's use of T-Mobile's licensed spectrum in the 1.6 GHz to 2.7 GHz range allows the satellite signals to act somewhat like roaming partner arrangements between operators. This helps with integrating Direct-to-Cell services into the existing regulatory and technical frameworks globally.

While the initial test is encouraging, significant work remains: scaling the satellite fleet, managing latency, ensuring battery performance in devices, handling data throughput, regulatory certification, and cost-model sustainability. However, this test demonstrates that direct satellite-SMS via unmodified phones is technically feasible and may soon offer a viable extension of mobile coverage in remote, underserved, or disaster-prone areas.