Most smartphones now support eSIM, allowing you to sign up for and use mobile networks without switching physical SIM cards. Some carriers now offer free trials via eSIM, which can be incredibly useful during travel in the US.

If you’re not familiar with eSIM, it’s a technology supported on many modern iPhone, Android, and iPad devices that replaces physical SIM cards. Instead of going to a store and getting a SIM card for a new phone plan or waiting for one to ship to you in the mail, eSIMs can be activated through apps on the phone or QR codes. It’s especially useful for temporary international cell service, but eSIM also comes in handy for trips within the United States.

How Do eSIM Trials Work?

Some carriers are using eSIM for more than just fast signups and phone activations. A few networks also offer eSIM trials, where you can try out the company’s service for a limited time. In most cases, you just download their app, set up the trial (usually without any payment information), and the eSIM is registered and activated on your device.

The best part is that most phones with eSIM support also have dual-SIM, meaning your trial connection stays active alongside your current phone service. You can continue using calls and texts on your regular number, while switching between the eSIM trial and your regular phone service for data. When the trial ends, the eSIM simply loses service, and your existing number continues working as it always did.

These trials are intended to push potential customers to switch carriers, but you can also use them as temporary lines, and are especially useful during travel. At least some eSIMs offer unlimited data or close to it, so if your main number is on a plan with limited data, you have more breathing room for downloads or streaming media while away from Wi-Fi.

You can also set up your phone to switch networks based on the current signal. If you’re on Verizon and traveling to an area that has bad Verizon coverage, but you have an active T-Mobile eSIM, your phone could switch to the T-Mobile service automatically when needed so you don’t lose internet.

I signed up for T-Mobile’s 5G trial last year with my iPhone 15, alongside my regular Cricket service (which uses AT&T’s towers), and it was pretty cool having access to two networks from the same phone. I only noticed one area—a stretch of highway on the way to visiting family in another state—where my main Cricket phone number didn’t have service and caused my phone to switch to T-Mobile. I already have unlimited data on my main line, so the unlimited data on the trial wasn’t as useful to me.

Pick The Best Carrier

As of December 2024, T-Mobile Network Pass is the most generous eSIM trial. You get three months with unlimited calls, text, and data, though speeds may slow down after 50GB each month. You can’t use it for tethering or international travel, you can’t be an existing T-Mobile customer, and you can’t use it again for 12 months. Verizon has a 30-day free trial,Cricket Wireless has a 14-day trial with AT&T’s network, and Visible has a 15-day trial with Verizon’s network.

If you’re trying to maximize your coverage area, it makes sense to pick a carrier using different infrastructure than your main number. For example, a free trial on Visible wouldn’t give you better coverage if you’re already on Verizon, because Visible just uses the same Verizon towers.

Each carrier also has a different list of supported phones, so not all trials will work on all devices. As of December 2024, T-Mobile’s Network Pass only works on the iPhone XS/XR and later models, Google Pixel 3 and later, Galaxy S20 series and later, Galaxy Z Flip 4 and later, and Galaxy Z Fold 3 and later.