Without a physical SIM card to install into a phone, the eSIM card setup primarily takes place on the device. When purchasing or upgrading your mobile plan, your wireless carrier may give you an eSIM activation card with a QR code for you to scan and confirm the setup of your eSIM.

Alternatively, you may get the QR code through a carrier website or email. Another option is downloading the eSIM registration app associated with your wireless carrier and setting up your mobile plan.

Many smartphones that support eSIMs also have nano SIM compatibility, the thinnest and lightest physical option. Phones with a dual SIM feature allow for a physical SIM and an eSIM to support two phone numbers on a single device.

Flagship devices all have dual SIM support for physical and eSIM cards. Notably, Apple's most recent iPhone 15 models sold in the U.S. only use eSIMs.

One of the main benefits of using a smartphone that supports eSIMs is that you'll have an easier time switching mobile networks, especially when traveling. 

Depending on the model, iPhones can support eight or possibly more eSIM profiles, for example. While traveling, you can set up and switch to a local network digitally at your destination rather than having to switch your physical SIM for a local SIM.

The physical SIM standard gives you the freedom to move your card from device to device. However, the on-device eSIM leaves you at the mercy of your carrier, meaning you'll have to set up your eSIM again each time you want to change phones.

If you want to port your eSIM to a new device, you must download the profile from your previous phone. This process can have a high error rate and can lead to tedious calls with your wireless carrier's customer service to troubleshoot issues.

Similarly, if your phone breaks, you could lose your eSIM profile and data, leaving it up to your carrier to determine whether your profile is salvageable.

Though smartphone brands continue offering physical SIM options now, many are moving toward supporting eSIMs. Most notably, the latest iPhones sold in the U.S. only use eSIMs. Google Pixel owners are also being encouraged to move their numbers to eSIMs. These suggest that the industry is ready to make eSIM support the standard.

As time passes, more brands may slowly begin to release smartphones without physical SIM options, ushering in the official age of the eSIM.

Story editing by Carren Jao. Copy editing by Kristen Wegrzyn. Photo selection by Clarese Moller.