How FairSIM eSIM works
Everything from what an eSIM is to the one setting that fixes most “no connection” problems. Five minutes to read, one tap to install.
What is an eSIM?
An eSIM is a SIM card built into your phone. Where a physical SIM is a plastic chip you swap in a tray, an eSIM is a small chip soldered to the board that stores a downloadable profile. Install a profile and the phone behaves exactly as if you had inserted a SIM from that network.
Every iPhone since the XS has an eSIM next to the physical SIM slot and can run both at once. That is what makes travel eSIMs work: your home SIM keeps your number for calls and two-factor codes, and the FairSIM eSIM carries the data at the local wholesale rate.
A FairSIM profile stays on your phone after the trip. Next time, you buy a plan for the new destination in the app and it loads onto the same eSIM. There is nothing to scan, post or pick up. Every country and regional plan is listed in the eSIM store, with coverage, data guidance and local tips for each destination.
Is my phone compatible?
FairSIM is available for iPhone. Your phone must support eSIM and be carrier-unlocked. iOS 17.4 or later unlocks the one-tap install with no QR code.
Works with FairSIM
- iPhone XS, XS Max and XR
- iPhone 11, 11 Pro and 11 Pro Max
- iPhone SE (2nd generation, 2020) and later
- iPhone 12 series
- iPhone 13 series
- iPhone 14 series
- iPhone 15 series
- iPhone 16 series
- iPhone 17 series
Does not work
- iPhone 8, X and older
- iPhones bought on a carrier contract that are still carrier-locked
- iPhones purchased in mainland China, and some Hong Kong and Macao dual-physical-SIM models
To check: open Settings, General, About. If you see an EID number, your iPhone has an eSIM. Settings, General, About, Carrier Lock should read “No SIM restrictions”.
How to get started
- 1
Pick a destination and a plan
Search the country or region above, or open the app and choose where you are going. Plans show data, validity and the full price. Nothing is added at checkout.
- 2
Pay in the app
Apple Pay or card, in the currency you see. The eSIM is provisioned in seconds and appears under eSIMs in the app.
- 3
Install before you fly
Tap Install. On iOS 17.4 and later the eSIM installs in one tap with no QR code. iOS will take you to Settings; label the line something like FairSIM Japan and come back to the app when done.
- 4
Land, turn on data roaming, connect
At your destination, turn the FairSIM line on, set it as your cellular data line, and enable Data Roaming for it. Your phone joins the partner network within a minute.
Install before you travel, activate on arrival
Most people assume installing starts the clock. It does not. These are two different moments.
Installing
Downloads the eSIM profile onto your phone. Needs Wi-Fi or data. Does not start the clock. Do it at home, a day or a week ahead, so nothing depends on airport Wi-Fi.
Activating
Happens when the eSIM first connects to a network at your destination. The plan's validity typically starts at that moment. Keep the line off until you land if you want every day of validity to count.
Turn on Data Roaming for the FairSIM line
This is the single biggest cause of “my eSIM doesn't work”. A travel eSIM is, technically, roaming on the local partner network, so iOS needs permission. It never bills you: roaming is what you paid for.
- 1
Open Settings, then Cellular.
- 2
Under Cellular Data, select the FairSIM line.
- 3
Tap the FairSIM line, then turn Data Roaming on.
- 4
Tap your home line and turn its Data Roaming off, so it never bills you.
Setup questions
My eSIM is installed but I have no connection. What do I check first?
Data roaming. Open Settings, Cellular, tap the FairSIM line and make sure Data Roaming is on. Then confirm FairSIM is selected as the line for cellular data. This one setting explains most connection problems.
Should I delete the eSIM when my trip ends?
No. Keep it installed and turn the line off. Next trip, buy a new plan in the app and it loads onto the same eSIM. Deleting it means reinstalling later.
Can I install the eSIM on a second phone?
An eSIM profile installs on one device. If you change phones mid-trip, contact support with your order details.
Does installing the eSIM use my data or start the plan?
Installing needs an internet connection, Wi-Fi is fine, and downloads a tiny profile. The plan's validity typically starts when the eSIM first connects at your destination, not at install.
What should I name the line during install?
Something you will recognise in Settings later, such as FairSIM Japan. iOS asks for a label during setup; the default is Travel.
Where do I find the QR code or manual details?
On iOS 17.4 and later you do not need them: the app installs the eSIM in one tap. Older iPhones can use the manual details shown in the app under your plan.
Ready to pick a destination?
Each destination page shows the partner networks, how much data your kind of trip needs, and the local rules that catch travelers out.
Get FairSIM on your iPhone
Free to download. Plans from $4.99. Track your data live, top up in seconds, and manage eSIMs for the whole group from one app.
iPhone XS or later · iOS 17.4+ for one-tap install
