Quick answer. In the US, all three major carriers — AT&T, Verizon, and T-Mobile — support RCS, along with UScellular and a long list of prepaid and MVNO brands (Cricket, Metro by T-Mobile, Visible, Xfinity Mobile, Spectrum Mobile, Boost, Consumer Cellular, TracFone/Straight Talk, and more). By the end of 2024 every major US carrier had added RCS, and all three majors now also support the new end-to-end-encrypted RCS on iPhone. Globally, RCS runs through Google's platform on most networks; for business messaging, reachable carriers vary by country and provider.
A key ecosystem shift: on Android, US carriers have standardized on Google Messages as the RCS client. Carrier-specific apps and older "Advanced Messaging" implementations are being retired in favor of Google's Jibe backend, so for most US Android users, RCS simply means Google Messages.
Because SimplyRCS is US-focused, the carriers that matter for its customers are the four US operators (AT&T, Verizon, T-Mobile, UScellular) plus their MVNOs — all of which support RCS, with SMS/MMS fallback covering any device or network that doesn't.
US carrier support at a glance (2026):
| Carrier | RCS support | Notes |
|---|---|---|
| T-Mobile | Yes | First US carrier to launch RCS; supports encrypted RCS on iPhone. |
| AT&T | Yes | Older "Advanced Messaging" RCS retiring July 2026 — RCS via Google Messages. |
| Verizon | Yes | Pushes Google Messages; ended Samsung Messages RCS Jan 2025. |
| UScellular | Yes | Supported; also charges A2P carrier surcharges. |
| MVNOs / prepaid | Mostly yes | Cricket, Metro, Visible, Xfinity Mobile, Spectrum, Boost, and others. |