Last updated 30 July 2026 · checked against iOS 26
Nine times out of ten it is Data Roaming switched off on the travel line. Turn it on: Settings → Cellular → [travel line] → Data Roaming.
If that was it, you can stop reading. If it wasn't, the rest of this page is organised by symptom rather than as a list of twenty things to try, because you have one specific problem and reading about nineteen others while standing in an airport is not help.
Key takeaways
Settings paths here were written against iOS 26. Android varies by manufacturer, so those paths are described by what you are looking for rather than an exact route. If your iPhone says Mobile Service instead of Cellular, you are on a non-US build — same menus, different word.
These two get mixed together everywhere, and they have nothing in common but the word eSIM.
| What happened | Which problem | Where the fix lives |
|---|---|---|
| Bought a travel data plan, landed, no service | Travel eSIM | This page, from here down |
| Your own phone number won't move to a new phone | Carrier eSIM | Your carrier — see the section near the end |
| Travel eSIM worked, then stopped mid-trip | Travel eSIM | "It worked, then it stopped" |
| New phone, everything gone | Carrier eSIM | Your carrier |
If it's the second kind, most of this page won't help you and no eSIM seller can fix it. Skip to the transfer section.
Before anything else, in this order. Most cases end here.
Still broken? Find your symptom below.
The status bar shows no network for the travel line, or shows it searching indefinitely.
This is the one. Your travel eSIM connects to a foreign operator's network, which is the definition of roaming, so the plan cannot work with roaming disabled. Turning it on for the travel line does not expose you to your home carrier's charges — that is a separate toggle on a separate line.
Installing a profile and enabling it are two actions. Settings → Cellular, tap the travel line, check Turn On This Line.
A locked phone will accept the profile, show it in the list, and then refuse to connect to anything. There is no error message explaining this, which is why it gets mistaken for a faulty eSIM more than any other cause.
Two things to know. Locking is invisible from the phone's settings — you cannot check it there. And it is separate from eSIM support: a phone can have perfectly good eSIM hardware and still be locked. Only your carrier can tell you, and only your carrier can unlock it.
Nothing on this page fixes a locked phone. Neither will support at any eSIM seller.
If someone has previously set network selection to manual, the phone will keep hunting for an operator that does not exist where you are. Settings → Cellular → [travel line] → Network Selection, turn Automatic on. If automatic fails, turn it off and choose one of the local operators from the list by hand.
Worth ruling out before you spend an hour on settings. Regional plans routinely exclude countries people assume are included.
The travel line shows an operator name and bars, and nothing loads. This is a different fault from "no service" and the fixes do not overlap.
Settings → Cellular → Cellular Data. If this says your home line, that is where your data is going — and, if that line has roaming off, nowhere at all. Set it to the travel line.
While you are there, turn Allow Cellular Data Switching off. Left on, it hands data back to the other line whenever the travel eSIM's signal dips.
Most travel plans configure this automatically. When it doesn't take, the line registers on the network but has no route to the internet — signal, no data.
The APN value is specific to your plan's operator. Any page that gives you one universal APN to type in is guessing. Get the exact string from whoever sold you the plan, then: Settings → Cellular → [travel line] → Cellular Data Network, and enter it in the APN field under Cellular Data.
Both look like a working eSIM with dead data. Check the remaining allowance and the expiry date with your seller before assuming a technical fault. Validity is usually counted from first connection, so a plan bought weeks ago may have started its clock the day you landed — or, on some plans, the day you bought it.
An eSIM profile is single-use. Once downloaded to a device it cannot be downloaded again, including onto the same phone after deleting it. If you removed the eSIM to "start fresh", that profile is gone.
This is the most expensive mistake in this article and it is easy to make, because deleting things and reinstalling them fixes most technology.
Scanning a code displayed on the same phone you are installing to is impossible. Use manual entry instead: you need the SM-DP+ address — the server the profile downloads from — and an activation code. Any seller worth using provides both alongside the QR. Settings → Cellular → Add eSIM → Enter Details Manually.
Downloading a profile needs Wi-Fi or working data. This is the argument for installing before you fly, while you still have both.
Different problem, and it is worth saying plainly because it fills the same search results.
This is about your carrier's eSIM — the one carrying your actual phone number — moving to a new device. It is handled between Apple and your carrier, using eSIM Quick Transfer or a replacement profile your carrier issues. No travel eSIM seller is involved and none can help.
If the transfer fails, your carrier is the only route. Ask them to reissue the profile.
Travel eSIMs generally do not transfer between devices at all. The profile is tied to the phone it was installed on. If you have changed phones mid-trip, expect to buy a new plan.
Every other page on this topic ends at "contact support". Here is the part they leave out.
If the plan genuinely does not work, you are owed a refund — from any seller, not just us. The circumstances that qualify are the same across any reputable provider:
What is generally not refundable, and it is fairer to know now than to argue later:
| Situation | Refundable? | Why |
|---|---|---|
| Device doesn't support eSIM | No | Checkable before purchase |
| Phone is carrier-locked | No | Same |
| Unused data at the end of the trip | No | The plan was supplied as described |
| Validity ran out before you used it | No | Time-limited from activation |
| Weak signal where the local network is simply weak | No | Resellers don't control the operator's network |
That last row is the one worth internalising. A travel eSIM rides on a local operator's network, so its coverage is that operator's coverage. In a valley with no mast, no eSIM from any seller will help.
Ask with your order ID and the specific symptom. "It doesn't work" gets a slower answer than "installed, shows no service, data roaming confirmed on, iPhone 15, Osaka, since Tuesday."
We sell travel eSIM data plans, so treat this as context rather than advice.
Our refund policy treats installation as the point of no return rather than payment: uninstalled profiles are refundable in full for any reason, and the three failure cases above are refunded whatever the state. You can ask the assistant to check your remaining data or cancel an order without opening a support ticket.
None of that changes the diagnosis above. Work through the same symptoms whoever sold you the plan.
The single most common cause of a dead travel eSIM is Data Roaming switched off on the travel line — because it feels like the setting that protects you from charges, when for that line it is the setting that makes the plan work at all.
After that, the useful move is not trying twenty fixes. It is deciding which of three faults you have:
And if it turns out none of those apply because the profile was never issued or the plan wasn't what was described, that is a refund, not a troubleshooting problem.
Before your next trip, the pre-flight checklist for activating an eSIM on iPhone takes four minutes and prevents most of what is on this page.
Why is my eSIM getting no service?
Most often because Data Roaming is switched off for that line. A travel eSIM connects to a foreign operator's network, so it needs roaming enabled to work at all. After that, check the line is actually switched on and that the phone is not carrier-locked.
Why is data not working on my eSIM?
If you have signal but nothing loads, the phone is probably using a different line for data. Check Settings → Cellular → Cellular Data points at the travel line. If it does, the APN may need entering by hand — get the exact value from whoever sold you the plan.
Why is my phone not allowing an eSIM?
Either it has no eSIM hardware, or it is carrier-locked. Dial *#06#: an EID means the hardware is there. Locking is separate and invisible in settings, so only your carrier can confirm it.
How do I manually activate an eSIM?
Settings → Cellular → Add eSIM → Enter Details Manually. You need the SM-DP+ address and the activation code from your seller. Use this whenever the QR code cannot be scanned, which includes any time the code is displayed on the same phone.
How can I tell if the eSIM itself is faulty?
If the profile installed, the line is on, roaming is enabled, Cellular Data points at it, and it still will not register on any network after ten minutes, the problem is with the profile or the plan rather than your settings. That is the point to contact the seller with your order ID.
Can I reinstall an eSIM I deleted?
Usually not. Profiles are single-use, so deleting one normally consumes it permanently — even on the same phone. Do not delete a travel eSIM to troubleshoot it.
eSIM Tabby runs a Model Context Protocol server at
https://esimtabby.com/mcp, published in the MCP Registry as
com.esimtabby/esimtabby. An assistant connected to it can search
plans by country, read the coverage and validity terms, complete a purchase,
check remaining data, and cancel an order — in the conversation, without the
traveller being sent to a checkout page to type card details.
Prices are re-read from the provider at checkout rather than taken from the tool call, so a wrong or forged argument cannot change what is charged. Payment goes through Stripe's hosted page, so no assistant ever handles card details.
What that is worth on this page: the diagnosis above is the same whoever sold you the plan, but the two things it repeatedly tells you to go and check — your remaining allowance and your plan's exact APN — are a question away rather than a support ticket, if the plan came from here.