Getting an older parent's phone ready for a trip: do it together, before they go

Why it cannot be done from your phone

The eSIM is downloaded by the phone that scans the code, and once installed it stays on that phone. If you scan your mother's QR code on your own phone to see whether it works, the plan is now on your phone, not hers. Sending her a photo of the code is not much better: she needs it on a second screen or on paper to scan it, or has to follow the steps in installing an eSIM without scanning the QR code.

Remote help has limits too. Apple lets someone request remote control of an iPhone during a one-to-one FaceTime call when both phones run iOS 18 or later and the person is saved in contacts, but Apple's own guide notes that remote control is not currently available in the European Union. Plain screen sharing still works: you see their screen and can tap or draw on it to point at the right button, while they do the pressing.

One afternoon, in this order

• Check that the phone takes eSIMs and is unlocked.
• Install the eSIM on home Wi-Fi, with the QR code on your laptop screen.
• Rename the lines to something obvious, such as Home and Travel.
• Turn off data roaming on the home line.
• Download an offline map of the place they are going.
• Show them, on the screen itself, the one switch to turn on when they land.

The first step decides everything else, so start there: how to check whether a phone supports eSIM and whether it is unlocked. Renaming the lines takes a minute and saves a confused phone call later; here is how. Doing it days ahead costs nothing: the plan only starts counting at the first connection at the destination.

Make the screen easier to read

On an iPhone, Apple puts the text size in Settings, Display & Brightness, Text Size. For larger options, go to Settings, Accessibility, Display & Text Size, Larger Text. Apple warns that very large text can make some buttons harder to tap, so try a few apps before you leave it set.

On Android, Google's help says to open Settings, search for Font size and move the slider; the font can go up to 200%. The setting does not apply in some apps, and Display size, next to it, enlarges buttons and icons as well. Bold text is in Accessibility, Display size and text. It is worth doing this before installing anything, so they can read every screen you go through together.

Health details a stranger can read

If something happens abroad, the people helping may not speak their language or know their passcode. On an iPhone, Medical ID lives in the Health app: tap the profile picture, then Medical ID, fill in medications, allergies and conditions, and turn on Show When Locked so it can be opened from the Lock Screen without the passcode.

On Android phones with Google's Safety app, open it, tap Your info and add Medical information and Emergency contacts. To make them visible on a locked phone, Google lists Emergency info access, then Show when locked. Google is clear that anyone who picks up the phone can then read that information, so include what helps in an emergency and nothing more.

A card for the moment they land

Write down, on paper, the three things they will need at the arrival hall: which line to turn data roaming on for, that WhatsApp keeps working with their usual number, and who to call if the phone shows no internet. Do not write the QR code or its activation code on that card; it is a one-use key and the reasons are in keeping your eSIM QR code private.

If something still goes wrong, a video call with screen sharing over the hotel Wi-Fi lets you see exactly what they see. Most first-day problems are the same few switches, covered in our guide to an eSIM with no internet. And if their phone turns out not to take eSIMs, Snoozim's compatibility list tells you before you pay rather than after.