eSIM Not Working? 7-Step Troubleshooting Checklist

Your eSIM installed fine, you've landed, and… no internet. Before you panic (or worse, delete the eSIM — don't delete the eSIM), run this checklist top to bottom. It's ordered by how often each fix works; most people are online again by step 3.

1. Turn on data roaming — for the eSIM line

The number-one cause, by a wide margin. Travel eSIMs are technically roaming profiles, so the eSIM line needs its Data Roaming toggle ON. This does not create roaming charges — the plan price is the plan price.

iPhone: Settings → Cellular → [your eSIM] → Data Roaming ON.
Android: Settings → Network/Connections → [your eSIM] → Data roaming ON.

Your home SIM's roaming can stay off — that's the one that costs money.

2. Make the eSIM your mobile-data line

The eSIM being on isn't enough; it must be selected for mobile data.

iPhone: Settings → Cellular → Cellular Data → choose the eSIM. Also turn Allow Cellular Data Switching OFF so iOS stops flirting with your home SIM.
Android: SIM settings → Mobile data → choose the eSIM.

3. Airplane-mode cycle (or restart)

Ten seconds of airplane mode forces the modem to re-register on the network — the classic fix for an eSIM that connected at the airport then sulked at the hotel. A full restart does the same job more thoroughly.

4. Pick the network manually

If your phone shows no bars or an emergency-only warning, it may be clinging to the wrong network:

iPhone: Settings → Cellular → [eSIM] → Network Selection → Automatic OFF, wait for the list, pick a listed partner network. If it fails, try another.
Android: [eSIM] settings → Mobile networks → Network operators → Search networks.

Once registered, you can flip back to Automatic.

5. Check the APN

Mostly an Android thing: if you have bars and an active data line but nothing loads, compare the APN against your confirmation email.

Android: [eSIM] → Access Point Names — add the APN from the email if it's missing, select it, restart.
iPhone: APN usually configures itself; if needed it's under Cellular → [eSIM] → Cellular Data Network.

6. Confirm the plan itself

Open the AeroCell app or your dashboard and check:

Is the plan actually activated? Validity starts at first connection in the destination — checking from home before the trip, it should say not-yet-active. That's normal, not broken.
Is the data used up? A depleted plan drops to zero silently. Top up in the app in seconds if so.
Right country? A Japan eSIM in Korea does nothing until you cross back.

7. Verify the phone is unlocked

If the eSIM installed but never registers on any network in any country, a carrier lock is the usual suspect. iPhone: Settings → General → About → Carrier Lock should read "No SIM restrictions". Android: ask your home carrier. Locked phones need the carrier to unlock them — there's no travel-eSIM workaround.

The one thing you should never do

Don't delete and re-add the eSIM. Travel eSIM profiles typically allow a single installation; deleting one usually burns it, and no amount of QR re-scanning brings it back. If you've exhausted this list, leave the profile in place and contact support — we can check the line's status from our side and reissue when appropriate.

Frequently asked questions

It worked yesterday and stopped today

Usually: data ran out (check the app), or the network needs a re-register — airplane-mode cycle, then manual network selection.

I get signal bars but WhatsApp says no connection

Data-line selection (step 2) or APN (step 5). Bars prove voice registration, not data flow.

iMessage/WhatsApp activation is acting weird

Both services keep using your home number — make sure your home SIM is still on (it needs no data, just presence) and set as the default for iMessage.

Still stuck?

Contact support with your phone model and destination — screenshots of Settings → Cellular speed things up enormously.

Before your next trip

Two minutes of prevention: install over home Wi-Fi, label the line, pre-set the toggles. Our installation guide shows the full pre-flight routine — including the one-tap install that skips half these steps.