Google RCS messaging has been live in the UK for a couple of weeks - but there is a problem that causes messages not to send. Fortunately, you can fix the problem quickly and easily, once you know you have a problem.
Google broke the deadlock on Android messaging, pushing out RCS - rich communication service - through its own servers rather waiting for mobile phone companies to offer that support.
Availability has rolled out to a range of users. It uses the latest Google Messages app on Android and we've used it on a number of different phones - the Pixel 3 XL, the Samsung Galaxy S10 and the Moto G7 Power for example - across a number of networks, EE and Three.
Once you've opted in, the system is designed to detect when people in a conversation are RCS-enabled and switch to using the data service for those messages, rather than SMS and MMS. That means you have full chat functionality for a messaging experience more like WhatsApp or Apple's iMessage.
Moving to RCS messaging is seamless - once you've enabled the service, it just happens.
What RCS through Google Messages isn't good at is telling you when the other person isn't RCS-enabled anymore. We moved a chat participant from an RCS-enabled device to an un-enabled device. In this situation, it should revert to SMS messaging, but this didn't happen automatically - instead it showed messages as "not delivered yet", because they couldn't be delivered via RCS.
There's no system notification for this, it's only in the Messages app against that specific message, so unless you go and check that message, you won't know that it hasn't sent. The non-RCS person will then not be receiving your messages.
It doesn't appear instantly which is part of the problem - it takes about 5 or 6 minutes before you'll see that the message didn't send, so it's not really a smooth experience. The first time it happened to us, it was 24 hours before we found that a collection of replies hadn't sent and we were in a one-sided conversation - we'd replied, closed the app and gone back to living our best life.
Tapping on the notification the Messages app will give you the option to send as "SMS/MMS instead". That gets around the problem of the other person being unable to receive those messages, so if that person is out of data - or beyond a data connection - this will push the message through on the older services.
However there's a little more confusion. That conversation with the failed messages doesn't then switch to SMS, it stays as an RCS chat, so even if you do manually push a message through SMS, the next will fail to deliver as it reverts to RCS again. To fix this problem, you need to head into the menu (top right), hit details and you'll find the option to send as SMS/MMS only. This effectively switches off RCS for a person who can no longer receive RCS messages.
Why might this situation occur? If someone never has any data and you want messages to get through then RCS might not be practical. Or, if they drop, lose or change phones to a device that's not supported, then you'll need to manually make this switch to fix your RCS messaging problem.