Install first: the 90-second bit
An iPhone 15 loads a travel eSIM in about two minutes, and the job is best done at your kitchen table rather than in an arrivals hall. Open Settings › Mobile Service › Add eSIM › Use QR Code, point the camera at the code WellRoam emails you, and tap through the prompts. If the QR code happens to be on the screen you are reading, choose Enter Details Manually and paste the activation string instead. That is all there is to iPhone 15 eSIM setup: no app to download, no shop queue, no fiddling with a tray.
- Join Wi-Fi and check Settings › General › Software Update — an iPhone 15 on iOS 26 handles multiple profiles far more gracefully than one still sitting on iOS 17.
- Settings › Mobile Service › Add eSIM › Use QR Code.
- Scan the code, tap Continue when the plan name appears, then Done.
- Leave Data Roaming switched on for the new line — that is how a travel profile finds partner networks abroad.
- Stop when iOS asks which line should do what. Everything below answers that question.
If step three raised eyebrows, our general installation guide covers the underlying theory once and properly, and a quick check of eSIM compatibility settles any doubt about older handsets in the household. From here on, we assume the profile is on the phone and you want to live with more than one line.
How many lines an iPhone 15 will actually hold
Every iPhone 15 stores at least eight eSIM profiles and keeps two of them active at the same time. That distinction matters more than the raw number: storing is free and permanent, activating is what costs you attention. Models sold in the United States (A2846, A2847, A2848, A2849) have no SIM tray at all, so both active lines are eSIMs. Everywhere else you get a nano-SIM tray plus dual eSIM support, which is the classic iPhone 15 dual SIM travel arrangement — home SIM in the tray, travel profile on top. Running multiple eSIMs on iPhone 15 is therefore normal use, not a workaround: three or four dormant destination profiles sitting in Settings cost nothing until you switch one on.
| Setting | Home line | WellRoam travel eSIM |
|---|---|---|
| Default Voice Line | Yes — keeps your number reachable | No |
| Mobile Data | Off while abroad | On |
| Data Roaming | Off (this is the bill-shock switch) | On |
| iMessage & FaceTime | Your usual number | Not needed |
| Allow Mobile Data Switching | Off — otherwise iOS quietly borrows the home line | |
Give every line a name you would recognise at 6am
The single best habit for anyone juggling several profiles is to relabel each one the moment it is installed. By default iOS calls things "Travel", "Secondary" or the operator's internal name, which tells you nothing when three profiles look identical. To label eSIM lines on an iPhone 15, go to Settings › Mobile Service, tap the line, then Mobile Plan Label and pick a custom name.
A naming scheme that survives four trips
- Country plus month: "Japan Oct", "Italy Mar" — you will know instantly which one has expired.
- Keep the home line as your own name or "Work", never "Primary", which iOS reuses confusingly.
- Add the data allowance if you buy several sizes: "Thailand 10 GB".
Labels appear in the Phone app, in Messages and on the status bar chevron, so a clear name is what stops you texting a client from a foreign number. If you want to rehearse the whole routine before a real departure, the free trial eSIM installs on your own iPhone 15 in the same two minutes and gives you a genuine second line to practise on.
Splitting the work: data on one line, calls on the other
The reason to run two lines at once is that they can do different jobs, and iOS 26 lets you assign each job separately. Three menus control everything, all inside Settings › Mobile Service: Default Voice Line, Mobile Data, and the per-line Data Roaming toggle. Set the travel eSIM as your data line and leave the home number as the voice line, and you get local speeds with your usual number still ringing. Turn off Allow Mobile Data Switching while you are at it, or iOS will fall back to the home line for a stubborn call and bill you for the privilege. You can watch consumption from the browser on our real-time data tracking page rather than guessing from the iOS counter, which never resets when you expect it to.
Install before you fly. Label before you land.
Switch the default line, not the whole phone.
Landing routine: what to change before you leave the aircraft
Knowing how to switch the default line on an iPhone 15 turns arrival admin into about five taps, done while the seatbelt sign is still on. Aeroplane mode keeps everything paused until you are ready, so run through this in order:
- Settings › Mobile Service › tap your travel line › Turn On This Line.
- Mobile Data → choose the travel line.
- Data Roaming → on for the travel line, off for the home line.
- Default Voice Line → leave on your home number so people still reach you.
- Switch off aeroplane mode and wait 60 seconds for the local network to attach.
If nothing attaches after two minutes, toggle aeroplane mode once more — that resolves the overwhelming majority of the arrival tickets we see. Frequent flyers on multi-country routes often skip the per-country shuffle entirely with a regional plan such as Asia (12 Areas), or browse the most popular destinations and keep two or three profiles stored permanently.
Back home: park the travel line, don't bin it
To turn off a travel eSIM on an iPhone 15, open Settings › Mobile Service, tap the line and choose Turn Off This Line — do not tap Delete eSIM. Turning a line off stops it hunting for networks and drops it out of the Phone and Messages pickers, while the profile stays stored for a future trip or for topping up. Deleting is permanent, and on most plans the QR code cannot be reused. Then reverse two settings: Mobile Data back to your home line, and Data Roaming off. Set a calendar reminder for the day your allowance expires if you are the sort of person who finds eleven dormant profiles a year later; anything genuinely dead can be cleared then, five seconds each.
When you probably don't need a travel eSIM
Honestly: not every trip justifies a second line. If you live in the EU and travel within it, roam-like-at-home rules mean your domestic bundle usually works across the bloc at no extra cost — check your fair-use cap and stop reading. Short UK or US business trips on a corporate plan with a roaming add-on are often covered too. A travel eSIM earns its keep when you leave your operator's free zone, when roaming is priced per megabyte, or when you want a second data line as backup on a working trip. It also helps if your travelling companion carries an older handset; a glance at which phones support eSIM saves an argument at the airport. Anything else — activation windows, top-ups, expiry dates — is answered on our frequently asked questions page.
Where to go next
Two lines on one iPhone 15 is a five-minute skill that pays back on every trip. Read the step-by-step installation guide if you want the full background, browse the destination guides for country-specific coverage notes, or pick up more practical advice in our tips and guides listing.
Still not convinced it will work on your handset? Install the free trial eSIM on your iPhone 15 tonight, label it, make it your data line for ten minutes, then switch back. If it behaves the way this article describes — and it will — you already know exactly what to do on landing day. Questions go to contact@wellroam.com and reach a human.