Before buying an eSIM for a trip, almost everyone asks the same question: does my phone need to be unlocked for it to work? The short answer is yes, but with an important nuance that almost no one explains well. You need an unlocked phone that is also eSIM-compatible: these are two different things and should not be confused. In this guide, we clarify this for you and show you how to check it yourself in one minute.
Does your phone need to be unlocked for an eSIM?
Yes. To use a travel eSIM, your phone must be both unlocked and eSIM-compatible (not carrier-locked and with the virtual chip). A phone locked to a specific carrier will reject any profile that isn't its own, so the eSIM will not connect.
The common confusion comes from mixing two concepts. "Unlocked" means the device is not tied to any specific carrier. "eSIM-compatible" means the hardware includes the virtual chip necessary to download profiles. You can have a compatible phone that is locked (it won't work) or an unlocked but old phone without an eSIM (it won't work either). You need both boxes checked. The good news is that most phones purchased in Spain in recent years already come unlocked from the factory, especially if you bought them outright without financing from a carrier. If you purchased it on installments with a carrier, it's more likely to be locked until you finish paying for it.
Unlocked phone vs. compatible phone: they're not the same
This is the point that causes the most problems. An unlocked phone accepts a SIM from any carrier; an eSIM-compatible phone can activate digital profiles without a physical card. These are independent requirements, and you need to meet both simultaneously for a travel eSIM to work.
A real example: someone with a high-end iPhone purchased with a contract can have a perfectly eSIM-compatible phone that, nonetheless, does not accept PuraSim's eSIM because it is still locked to their carrier. The reverse also happens: an unlocked phone from eight years ago accepts any physical card, but it doesn't have an eSIM chip, so there's nothing to install. That's why the correct check involves two steps, not one. If you want to delve deeper into just the technical part, we have a specific guide on how to check if your phone is eSIM-compatible and an updated list of eSIM-compatible phones.
How to check if your phone is unlocked
Checking if a phone is unlocked is simple and doesn't require any special tools. There are several ways, from the fastest to the most reliable:
- Try with another SIM: Insert a physical SIM card from a different carrier than your usual one. If it gets coverage and you can make calls without issues, it's unlocked.
- Phone settings: On some Android phones, a "network lock" or "SIM not allowed" message may appear. On iPhones, in Settings > General > About, it usually indicates "Carrier Lock: No SIM restrictions."
- Ask your carrier: If you bought it financed, the company can confirm if it's already unlocked and unlock it if you've finished paying.
Tip: In Spain, a phone bought outright at a general store or on Amazon almost always comes unlocked from the factory. The lock usually only appears when you finance the device with a carrier.
If you still have doubts after checking, calling your carrier is the most reliable option: they are obliged to inform you of your device's lock status.
How to check if it's eSIM-compatible
Once you've confirmed it's unlocked, it's time for the second check: eSIM compatibility. The quickest methods are these:
- Dial *#06# on the call keypad. If your phone is eSIM-compatible, an EID (a long number) will appear next to the IMEI. If no EID appears, your phone does not have an eSIM.
- Look for the "Add eSIM" option or "Add data plan" in your mobile network settings. If it exists, your device supports it.
- Check the model: iPhones from XS/XR onwards, Samsung Galaxy S20 onwards, modern Google Pixels, and many recent Xiaomi and Motorola phones already include it.
For details by operating system, you'll find our guide on installing and activating an eSIM on Android and the one on installing on iPhone useful. If you're still unclear on the concept, start with what an eSIM is.
What happens if your phone is carrier-locked
If you discover that your phone is locked, the eSIM will not connect, no matter how compatible the hardware is. The solution is to unlock it, and in Spain, it's a right: when you finish paying for a financed device, your carrier must unlock it, usually free of charge.
The process varies by carrier, but it usually involves requesting it by phone, through the app, or at a physical store, and waiting anywhere from a few hours to a couple of days. In the meantime, don't buy an eSIM "just in case": it's better to unlock it first and then purchase the plan, so that everything is ready on your travel day. Also, keep in mind that an imported phone from outside the European Union may be locked to a specific market, so always check its status before relying on it for international use. Once unlocked, the rest is identical to any unlocked phone, and installation will take you barely 1 minute.
Installing an eSIM on an unlocked phone step-by-step
With your phone confirmed as unlocked and compatible, activating a travel eSIM is one of the easiest things you'll do before you leave. The general flow is this:
- Purchase the plan for your destination country or region and receive the QR code by email.
- At home and with Wi-Fi, go to Settings > Mobile Data > Add eSIM and scan the QR code.
- Name the line (e.g., "Travel") and keep your Spanish line for calls and SMS.
- Upon landing, activate the travel eSIM for data and voilà: you'll have internet as soon as you get off the plane.
The table summarizes the difference between the two key checks so you don't mix them up:
| Requirement | What it means | How to check |
|---|---|---|
| Unlocked phone | Not locked to a specific carrier | Another SIM works / Settings / Ask the carrier |
| eSIM-compatible | Hardware with eSIM chip | Dial *#06# and look for the EID |
| Result | eSIM ready for travel | Both boxes checked |
For complete installation details, you can refer to the guide on how to install an eSIM and how to buy an eSIM online.
Frequently asked questions
Can I use an eSIM if my phone is carrier-locked?
No. A locked phone rejects any profile that is not from its carrier, so the travel eSIM will not connect even if the hardware is compatible. You must first unlock the device, which your carrier should do free of charge once you have finished paying for it.
How do I know if my phone is both unlocked and compatible?
There are two checks. To find out if it's unlocked, insert a SIM from another company or check it in Settings. To find out if it's eSIM-compatible, dial *#06# and look for an EID number next to the IMEI. If you have both, your phone is ready.
Is an unlocked phone always eSIM-compatible?
Not necessarily. An unlocked phone simply means it accepts any carrier. eSIM compatibility depends on the hardware: models prior to 2018 and many low-end phones do not include it, even if they are perfectly unlocked.
Does unlocking a phone cost money in Spain?
Generally not. When you finish paying for a financed device, your carrier is obliged to unlock it, usually for free. The process can take from a few hours to a couple of days depending on the company, so do it before your trip.
Can I have an eSIM and my Spanish SIM at the same time?
Yes. eSIM-compatible phones work in dual mode: you keep your Spanish card for calls and SMS and use the travel eSIM for data. This way, you keep your usual number while browsing with the local rate at your destination.
Conclusion
To use a travel eSIM, you need a phone that is both unlocked and eSIM-compatible: these are two distinct requirements that are easy to check in a minute with a test SIM and the code *#06#. If your device meets both, you can forget about expensive roaming and travel connected from the first minute. Check your phone, choose your destination, and activate your eSIM before you leave to arrive with internet ready. Discover all PuraSim plans for your next trip.
