Lance Whitney/ZDNETWith the launch of iOS 18, iPhone users are finally able to exchange rich text messages with their Android counterparts. But beyond Apple’s support of RCS, each carrier needs to activate the capability — and for now, many carriers have yet to jump on the bandwagon.Also: 8 ways I’m preparing my iPhone for iOS 18 – and I recommend you do tooRCS, or Rich Communications Service, is a messaging standard released by Google a few years ago. Designed to replace SMS messaging, RCS is a more modern standard that can handle richer content. With RCS enabled, texts from your iPhone to Android users can include larger file attachments, higher-quality photos and videos, audio messages, read receipts, more types of emojis, and smoother group chats.In the US, RCS is available on the iPhone via the three major carriers (AT&T, Verizon, and T-Mobile), many regional providers, and a few mobile virtual network operators (MVNOs). RCS support also varies across Europe, Asia-Pacific, Africa, Latin America, the Middle East, and India. In general, the major carriers tend to offer it; the smaller ones, not so much.Specifically, support for the iPhone is still limited among MVNOs, according to Ars Technica. Such operators typically offer pre-paid services but then piggyback on the networks of major carriers to provide the actual connectivity. In the US, for example, Consumer Cellular, Cricket, and US Cellular have all implemented RCS for the iPhone. But other MVNOs in the US, such as Boost Mobile, Mint Mobile, Simple Mobile, and Ultra Mobile, have yet to hop onboard.Also: iOS 17.7 rolls out this week – here’s why it might be a safer bet than iOS 18As one outstanding absence, Google Fi doesn’t yet support RCS from the iPhone. The irony here is that Google pushed RCS as a standard in the Android world and shamed Apple into implementing it on the iPhone. Apparently, though, Apple still has more to do to enable RCS for iPhone users on Fi than simply supporting the capability with iOS 18. More