Does your phone have a dual SIM tray or eSIM support? You probably know it lets you add a second phone number, but a secondary SIM opens up a world of possibilities you may not have considered. Let’s explore some real-world, practical use cases beyond the obvious.
If you have a recent phone, there’s a very good chance it supports both a physical SIM and eSIM. Everything below works whether you have a dual SIM tray or eSIM — and eSIM-only phone users can try these too. Just make sure you have an unlocked phone, since some carriers will block you from adding a secondary plan from another provider.
1. Keep a Travel-Only SIM
When traveling abroad, you used to have to visit an airport kiosk and buy a local SIM with a preloaded data plan. There’s almost no need to do that anymore. Instead, maintain a travel-only SIM that you activate when abroad and disable when you return home, buying data plans as needed for whichever country you’re visiting. It’s almost always cheaper than inflated airport rates, and it means you have data the moment your plane touches down.
One service I’ve used in multiple countries without issue is Ubigi, an eSIM-only provider offering affordable data plans for a long list of destinations. Once you install the eSIM, just purchase a data plan for wherever you’re going and activate the eSIM when you arrive. It’s data-only, so there won’t be an extra number getting calls and texts. Ubigi is just one option in a sea of competitors offering a similar service.
If you prefer a physical SIM for your dual SIM tray, companies like OneSimCard offer physical SIMs with great ratings on Trustpilot — though it’s always worth shopping around.
2. Get Better Coverage Everywhere You Go
Mobile reception has improved over the years, but it’s entirely possible to have a phone plan with a dead zone where other carriers provide solid coverage. Dead zones can be more than just an annoyance if you need to stay connected for work or be reachable during an emergency while traveling between cities or states. That’s where a second phone plan can really help.
There’s no need to go with an expensive plan. Pick up an affordable plan from one of the many US budget carriers, ideally finding something that overlaps those weaker areas. Some carriers let you customize your plan down to a bare-bones data-only or talk-only configuration. $6 a month isn’t bad at all if it helps extend your coverage and give you peace of mind.
One downside: your battery will drain slightly faster running two SIMs. The drain is worse when your phone is in a weak-signal area for the secondary network. Mitigate this by disabling that secondary SIM when not needed, or using Wi-Fi calling in areas with poor signal.
3. Keep a Burner Number
A secondary, throwaway number may sound like something from a spy movie, but in an age of relentless robocalls and AI voice-cloning scams, having a number you can give to people you don’t fully trust is just smart. Anytime a website will send you marketing texts, or an account requires a number for sign-up, or someone you’d rather avoid is hitting on you, you’ll be glad you had it. Save your real number for close friends, family, banking, and anything truly important.
Go for a cheap plan here. Tello lets you build a 300-minute, no-data plan for just $5 a month. Since Tello uses eSIMs, it’s easy enough to burn a number and start fresh if needed. Tello also offers physical SIM cards. Just note that Tello only lets you change your number once for free.
4. Use Your Personal Phone for Work Without Losing Your Sanity
Ideally, you’d have a separate work phone. But not everyone is that lucky. A second SIM card (and a few settings adjustments) can create an effective wall between personal and work life on a single device.
Two separate numbers naturally divides your life in half. Both Android and iOS let you choose the default number for texts and calls, and even select which SIM to use before each call or text. Both also support Focus modes that control how and when notifications come through, making it easy to silence work contacts during off-hours. Android also offers a second user profile and dedicated work profiles, further confining work to its own unobtrusive box. Software-based work/personal separation is so good right now that a separate work device almost feels unnecessary.
5. Live Abroad as If You Were at Home
Anyone who has lived abroad knows the small things cause the biggest headaches. Many online accounts (like banking) require a phone number based in your home country and reject app-based VoIP numbers. Major carriers may charge exorbitant rates to use an existing number abroad. The key to avoiding these costs — while keeping a working phone number for occasional OTP codes and customer support calls — is using Wi-Fi calling on a second SIM.
Wi-Fi calling routes texts and calls over the internet instead of through a cell tower, giving you full access no matter which Wi-Fi network you’re connected to. Just make sure you have a carrier that supports it without restrictions on international texts and calls. Since you’re likely already paying for mobile data in your current country, pick up an affordable plan (Tello’s $5/month plan supports international Wi-Fi calling) just to receive your calls and texts.
In my experience, this is the best way to live abroad while maintaining a fully functional home number. Set up the SIM for your home country before traveling abroad, as setting it up internationally can be tricky.
