Here's how you can try T-Mobile's wireless network for up to 30 days at no cost
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Regardless whether you're an iPhone or Android user, if you are a customer of any wireless provider in the U.S. other than T-Mobile, the latter is giving you the opportunity to try out its network at no cost for 30 days or 30GB of data, whichever comes first. To take advantage of the T-Mobile Network Test Drive, simply follow these easy steps.

If your iPhone is connected to your carrier by an eSIM, you cannot use the app to connect to T-Mobile because you will end up disconnecting from your current carrier. If you are using a SIM card, your iPhone will connect to the T-Mobile Network in a jiff if you follow the directions included on the app. If your iPhone does use an eSIM, you can still participate in the trial by requesting a hotspot like Android users have to.
Things that are NOT allowed: