People who are new to travel eSIMs often assume they work like regular SIM cards — that you swap one out for the other. This makes sense as a mental model, since that's exactly how physical SIMs work. But eSIM is different. There's nothing to physically insert or remove. The profile is software, stored on a chip that's already in your phone.
The practical consequence: you do not need to remove your physical SIM to use a travel eSIM. In most cases, you actively shouldn't.
How Both Coexist in Your Phone
Modern smartphones with eSIM capability are designed to run both a physical SIM and an eSIM profile simultaneously. This is called Dual SIM mode, and it's the standard configuration for travel. Your physical SIM stays in the tray. The eSIM profile is installed and runs as a second line. You configure which line handles data in your phone settings — typically the eSIM for cheap local data — while calls and SMS continue on your physical SIM.
This is precisely why eSIM is useful for travelers. The whole point is that you don't have to choose between your home number and local data. You get both at the same time.
Why You'd Keep Your Physical SIM In
Your physical SIM carries your home phone number. Everything tied to that number — WhatsApp, banking apps, authentication codes, incoming calls — depends on that SIM being present and active. Remove it and you lose all of that for the duration of your trip.
Travelers who remove their home SIM and rely entirely on the eSIM (which is usually data-only with no associated phone number) often run into problems they didn't anticipate:
- Bank apps can't send OTP codes to the number on file
- Calls to their regular number go nowhere
- WhatsApp still works for sending messages, but receiving calls requires someone to know your WhatsApp number specifically
- Hotel reservations or service callbacks to your number fail
- Family members can't reach you on your normal number
None of these problems arise if you simply leave the physical SIM in the phone.
Keep your physical SIM in your phone. Set the eSIM as your data line. Your home number stays active and reachable, while your internet traffic runs through the much cheaper local eSIM connection.
When Removing the Physical SIM Might Make Sense
There are specific situations where removing a physical SIM is reasonable — though they're less common for short-trip travelers.
You're on a long trip and have no reason to receive calls on your home number
If you're traveling for months, working remotely, and have deliberately moved all your communications to VoIP apps and a different number system, carrying a home SIM you never use is just a battery drain and a potential source of accidental roaming charges. Some long-term travelers remove the home SIM and manage without it. This is a deliberate choice, not a necessity.
Your phone only has one physical slot and you want to add a second local SIM
This is the scenario where the choice gets more meaningful. If your phone is eSIM-only (no physical slot), this isn't a concern. But if you have a physical SIM slot and want to install a local physical SIM — for example, you bought one at the airport — you'd have to remove your home SIM to do so. An eSIM sidesteps this entirely: you keep the home SIM in and install the local data plan as an eSIM instead.
Your carrier's roaming charges apply even to idle SIM cards
Some carriers charge a daily roaming fee the moment their SIM is in a device that connects to a foreign network, even if you make no calls or use no data. If your carrier works this way and you can't disable roaming, removing the SIM prevents the charge. Before doing this, check whether you can simply disable roaming in your carrier account — this is usually possible and avoids the need to physically remove anything.
If you do remove your physical SIM, store it somewhere safe and memorable. SIM cards are small and easy to lose in luggage, hotel rooms, or travel wallets. Losing your home SIM can be an expensive problem to fix when you get back.
Managing the Data Line on Your Physical SIM
Keeping your physical SIM in the phone while using eSIM for data requires one configuration step that some people miss: you need to disable mobile data on the physical SIM line and enable it on the eSIM line.
If you don't do this, your phone may try to use your home carrier's roaming data — which is expensive — in addition to or instead of the eSIM data. The setup process in your phone's cellular settings looks like this:
- Go to Settings → Cellular (iPhone) or Settings → SIM card manager (Android)
- Find the option for "Cellular Data" or "Mobile Data"
- Select the eSIM line as your data source
- Make sure mobile data on the physical SIM is turned off
Your physical SIM stays active for calls and SMS. The eSIM handles data. No roaming charges accumulate on the physical SIM line because it isn't being used for data at all.
The setup guide covers this configuration step in detail for both iPhone and Android.
What About Roaming on the Physical SIM?
Even with mobile data disabled on your physical SIM, the SIM still registers on a foreign network to handle calls and SMS. This is usually called "voice roaming" and is cheaper than data roaming — and often included in plans without extra charge.
However, whether your physical SIM registers at all abroad depends on your home carrier's roaming policy. If international roaming is completely disabled on your account, the SIM won't connect to any network in the destination country, and you won't receive calls or SMS on your home number. You'd need to enable roaming (even just voice roaming) in your carrier account settings before leaving.
This is a minor prep step that takes about two minutes and makes a significant difference to your accessibility while abroad.
The Situation with eSIM-Only Phones
A growing number of phones — particularly recent iPhone models sold in certain markets — don't have a physical SIM slot. Everything runs as eSIM profiles. If you have one of these devices, the question of removing a physical SIM doesn't apply.
Instead, you manage two eSIM profiles: your home carrier profile (which holds your regular number) and the travel data eSIM profile. Both are stored on the device. You activate the travel eSIM for data while keeping your home profile active for calls and messages. The behavior is functionally identical to the physical SIM + eSIM setup described above.
The setup steps are the same: select the travel eSIM as the data line, keep your home profile active for calls and SMS.
A Note on Physical SIM Damage and Wear
One practical advantage of leaving your physical SIM in place during travel is reduced wear and risk. SIM card trays are prone to damage if opened frequently. The tiny SIM card itself can be lost, bent, or damaged if you're pulling it in and out regularly. Leaving it installed for the duration of a trip avoids this entirely.
There's no good reason to remove it for a week or two of travel. It takes up no battery, no space you'd otherwise need, and no meaningful processing power while sitting idle as a registered voice line.
See the available travel eSIM plans at eSIM destinations and verify your phone's compatibility at compatible devices. For a walkthrough of the full installation process, the eSIM activation guide has step-by-step instructions.