Setting up WhatsApp and your number for a trip

A travel eSIM adds a line for data and leaves your usual SIM where it is. That makes keeping your number easy, as long as each line has the right job. This is the list to go through on the phone before you leave.

Before you go

• Ask your carrier whether your line works where you’re going, and what calls and texts cost there. Your number stays on your usual SIM, so its calls and texts are your carrier’s.
• Add an email address to your WhatsApp account in its settings. If you ever have to register your number again while you’re away, WhatsApp can send the code to that email.
• Install the travel eSIM at home, on Wi-Fi. Our guides for the iPhone and for Android go through it.

Give each line one job

With two lines on, the phone uses one cellular data network at a time. On a Pixel, Google puts it the same way: only one SIM can be the default for data. So set the two like this.

• Calls and texts: your usual line. On an iPhone it’s the default line; on Android, the SIM chosen for calls and for texts.
• Mobile data: the travel line, once you’ve arrived.
• Data roaming: on for the travel line and off for your usual one, so your number keeps working without your usual SIM using data abroad.
• On an iPhone, iMessage and FaceTime stay on your usual number. Apple says that even if you use only the travel eSIM, FaceTime and iMessage keep working on your home line.

In WhatsApp

• Nothing to change for your number. WhatsApp uses the same internet connection as web browsing and email, so it runs over whichever line carries your data, and your account stays on your usual number.
• Set Media auto-download to Wi-Fi, under Settings, then Storage and data, so the photos and videos in busy groups don’t use your travel data before you open them.
• In the same place, Network usage shows what WhatsApp itself has used.

While you’re away

• Keep WhatsApp where it is. To verify a number, WhatsApp needs that number’s SIM in the phone, with phone or SMS service enabled, so reinstalling it or moving it to another phone abroad can leave you locked out until you’re back.
• Keep your usual SIM switched on if you need its texts, such as your bank’s one-time codes. They go to your number, not to the travel line.
• Keep the travel eSIM when its data runs low. Where it can take a top-up, adding data keeps the same eSIM, and its code works only once.

Back home

Choose your usual line for mobile data again and turn the travel line off. On recent iPhones this can happen by itself: depending on the country, the iPhone can turn off your travel eSIM and turn your home SIM back on when you return.