Short answer: install your 4S eSIM within 1 month before departure, while you have stable Wi-Fi.
Recommended timing
- Install the eSIM within 1 month before your trip.
- Install before departure so you are not troubleshooting at the airport or after arrival.
- Use stable Wi-Fi during installation.
- Do not delete the eSIM after installation.
Installing and activating are not the same. Installation adds the eSIM profile to your phone. Activation happens on first use, when the eSIM connects and starts the data plan.
Why not install too early?
Some carriers require authentication and compliance checks for eSIM profiles. Installing too far ahead of your trip may increase the chance of a PDP Authentication Failure or similar network authentication issue later. For best reliability, install within 1 month before departure.
After installation
- Keep the eSIM installed on your phone.
- Do not delete it unless your trip is over and you no longer need the plan.
- At your destination, select the label used for your 4S eSIM as mobile data and turn on data roaming for that same line.
When your phone asks you to name or label the eSIM during installation, choose a clear label you will recognize later, such as 4S eSIM, your destination country or region, or Travel. If you did not rename it, look for the newly added eSIM, a travel/secondary/business label, or the line that shows No Number.
Do not delete the eSIM after installation. Most eSIM profiles can only be installed once.
Need help?
If you are not sure whether to install now, contact 4S support through support@4s.net, a Zendesk support ticket, or Zendesk live chat. Do not reply to hi@4s.net; it is an automatic email sender.