When traveling abroad, the last thing you need to worry about is whether your cellphone will work.

So, experts say you should plan ahead.

The reason? Your cellphone will automatically switch to the mobile carrier that you have, and it will mean an added cost to your trip.

“Verizon and Xfinity for example, they charge you $10 per day, per line for their day passes for international roaming. So, that’s $20 a day for a couple using two phones,” Kevin Brasler, executive director at Washington Consumer’s Checkbook, told WTOP.

But Brasler said you can cut your bill in half.

“One is to use your phone but to swap in a foreign SIM card or download an eSIM. You can buy these at countries you’re visiting and often even at the airport. This basically shifts you to a foreign service,” Brasler said.

Brasler said there are more ways to save.

“Another option is to put your phone in airplane mode for the trip and rely on Wi-Fi. In most foreign cities, free Wi-Fi is widespread, and you can still use it to send free messages, like WhatsApp, FaceTime or Teams,” Brasler said.

Some other tips for using SIMs and eSIMs:

• If your phone uses a physical SIM card, make sure to bring along a SIM needle. It resembles the end of a paper clip and is used to pop open your phone’s card tray. We’ve heard from subscribers who broke their phones using wooden toothpicks and other apparatuses trying to pry this open.
• If you swap out physical SIM cards, make sure to stash the original in a safe place after you remove it.
• Consider keeping in touch using WhatsApp so your contacts back home don’t rack up a bill texting with a foreign phone number.
• If you’re going away for a month or longer, consider freezing your account with your U.S. carrier to avoid paying double for coverage. AT&T, T-Mobile and Verizon allow this for up to 90 days.