iOS 18.4 is currently in beta testing, and with the recent beta 2 debut, it brought long-awaited RCS messaging support to not only Google Fi users, but also customers of some other big US carrier holdouts: Mint Mobile, Boost Mobile, and more. Here are the details.Mint Mobile and Boost Mobile now support RCS, alongside Google Fi and moreRCS messaging is a newly supported feature in iOS 18 that makes texting between iPhones and Androids perform way better than before.Thats because RCS is a more modern messaging protocol than SMSthe previous standard for non-iMessages.But due to the way the technology works, Apple adding RCS support in iOS 18 did not automatically bring the feature to all iPhone users. Instead, each carrier had to implement its own RCS support.All of the biggest US carriers have supported RCS on iPhone for a while, including AT&T, Verizon, and T-Mobile.Plenty of smaller carriers have also enabled RCS messaging. But some of the main holdouts to this point have been T-Mobile MVNOs like Mint Mobile and Google Fi.Now, with iOS 18.4, theres full RCS support for all T-Mobile MVNOs such as:Metro by T-MobileMint MobileBoost MobileGoogle Fiand moreRCS compatibility and features in iOS 18.4If youre running iOS 18.4 beta 2or when you install the public release of iOS 18.4 next monthyoull be able to start using RCS in the Messages app immediately.You can verify that your carrier is now supported in one of two ways:Go to Settings Apps Messages then scroll down to the RCS Messaging sectionOr to go Settings General About and tap the Carrier row to see if RCS is listedSome of the benefits of RCS over SMS is that it supports several iMessage-like features, such as:tapback reactionssending higher quality photos and videosread receiptstyping indicatorsiOS still displays green bubbles for RCS conversations rather than blue ones, but generally you shouldnt experience some of the same issues with RCS that SMS tends to cause.Are you excited for RCS to come to Mint Mobile and Google Fi? Let us know in the comments.Best iPhone accessoriesAdd 9to5Mac to your Google News feed. FTC: We use income earning auto affiliate links. More.Youre reading 9to5Mac experts who break news about Apple and its surrounding ecosystem, day after day. Be sure to check out our homepage for all the latest news, and follow 9to5Mac on Twitter, Facebook, and LinkedIn to stay in the loop. Dont know where to start? Check out our exclusive stories, reviews, how-tos, and subscribe to our YouTube channel