Did you get a text message from T-Mobile telling you that you should swap your SIM card to get the best 5G experience? If so, you’re not alone.

T-Mobile is sending texts to some customers this week to remind them that it’s a good idea to upgrade to the new SIM card that’s included when they buy a new device. The text includes a link to this web page explaining why you might need to upgrade to a new SIM.

To access T-Mobile’s standalone 5G coverage, your SIM card will need to be compatible with it. You can check to see if your SIM is compatible now by pulling it out of your device and checking to see if it says “R15”. If it does, you’re good to go.

If you see “TM” followed by four numbers on your SIM, you’ll need to switch to the new SIM card that came with your device.

If you’ve got a 5G device, it should’ve come with a new SIM that you could use with it. If you didn’t start using the new SIM and for some reason you no longer have it, you should contact customer support and get a free replacement.

T-Mobile activated its standalone 5G last month, and when it did T-Mo increased its overall 5G footprint by 30 percent. Standalone 5G also enables lower latency.

Currently there are only a handful of T-Mobile phones that’ve been updated to support standalone 5G, with the Galaxy Note 10+ 5G receiving an update to enable it today. T-Mo is planning to update more of its 5G phones to support standalone 5G, though, so even if your device doesn’t support the feature yet, it’s definitely worth taking a minute now to check your SIM card and ensure that you’re ready for standalone 5G when it comes to your phone.

Source: T-Mobile