First: identify what “not working” means

Different symptoms point to different causes. Before you change settings, quickly classify the problem:

• eSIM won’t install: QR/manual install fails, “Cannot Add Cellular Plan,” or it never completes.
• eSIM installs but no service: the line exists, but shows “No Service,” “SOS,” or can’t register.
• Signal is present but no data: you see bars/5G/LTE but apps won’t load.
• It worked, then stopped: sudden drop after switching countries, updating OS, or reaching a data limit.

Most travel eSIM issues fall into the “signal present but no data” bucket. The fix is usually the data line selection + roaming toggle.

The 5-minute fix checklist (do this in order)

If you want the quickest path to a working eSIM, follow this sequence. Don’t skip steps. Each one rules out a common failure point.

1. Turn airplane mode ON for 10 seconds, then OFF.
2. Restart your phone (yes, even if you already toggled airplane mode).
3. Confirm the eSIM line is enabled (the line can be installed but turned off).
4. Select the eSIM as your Mobile Data/Cellular Data line (especially on Dual SIM phones).
5. Enable Data Roaming on the eSIM line if your travel plan requires it (keep roaming off on your primary SIM if you want to avoid charges).

Reason #1: you’re using the wrong data line (Dual SIM issue)

On iPhone and many Android devices, it’s very easy to install a travel eSIM and still be using your home SIM for data. Then you disable roaming (good), and suddenly “the eSIM doesn’t work” (not true). The phone is simply using the wrong line.

Fix on iPhone

• Settings → Cellular/Mobile Data → Cellular Data → select your eSIM
• Settings → Cellular → tap your eSIM line → ensure Turn On This Line is enabled

Fix on Android (general)

• Settings → Network & Internet/Connections → SIMs → select the eSIM for Mobile data
• Ensure the eSIM toggle is enabled and preferred for data

Label your eSIM (e.g., Zetsim Travel). “Primary” and “Secondary” are how mistakes happen.

Reason #2: Data roaming is off (on the eSIM line)

Many travel eSIMs use roaming agreements to connect you to partner networks. That can require Data Roaming to be enabled on the eSIM line. Travelers often turn roaming off everywhere to avoid fees, then wonder why the eSIM won’t connect.

The clean approach: enable roaming on the eSIM line if required; keep roaming off on your primary SIM if you don’t want your home carrier to roam.

Where to check

• iPhone: Settings → Cellular → eSIM line → Data Roaming
• Android: Settings → Connections/Network → Mobile networks → Data roaming

Reason #3: the eSIM never fully activated (installation vs activation)

Sometimes the profile installs but doesn’t register correctly. This usually happens when installation was done on unstable Wi‑Fi, the device was switching networks, or the phone didn’t refresh its registration after setup.

Fixes that help registration

• Restart the device after installation
• Toggle airplane mode
• On iPhone, check that the eSIM line shows as enabled and selected for data
• On Android, re-check that the eSIM is selected as the preferred data SIM

If you’re still at home, reinstalling can be easier than troubleshooting on the road. If you’re already traveling, start with network selection and roaming checks first.

Reason #4: network selection is stuck (Automatic vs manual)

Phones sometimes cling to a weak network or fail to reselect after you land in a new country. If you have signal but data doesn’t move, forcing a network refresh can help.

What to try

• Toggle airplane mode
• Restart the phone
• If your device supports it: turn Automatic Network Selection off, wait for networks to populate, pick one, then return to Automatic

This is especially relevant when you cross borders or move from a dense city area to a rural area.

Reason #5: APN or cellular data settings are incorrect (data but no internet)

If you have bars and the eSIM looks active, but nothing loads, the issue can be the data path (APN) or device-level restrictions like VPN, private DNS, or content filters.

Fixes to try

• Disable VPN temporarily and test again
• Disable Private DNS (Android) temporarily
• Reset network settings (more on this below) if nothing else works

VPNs are great until they break captive networks or block a roaming data route. Don’t uninstall—just test without it.

Reason #6: your phone is carrier-locked (the hard stop)

If the phone is locked to your home carrier, the eSIM may install but fail to register, or it may refuse to activate in the first place. This is common with phones purchased on installment plans.

What you can do: confirm unlock status with your carrier. There’s no magic in settings that bypasses a carrier lock.

Reason #7: you ran out of data, the plan expired, or a top-up is needed

Sometimes the eSIM “stops working” because the data allocation is finished or the validity period ended. This looks like a technical problem, but it’s just a plan status issue.

• If you have a way to check usage in your eSIM provider portal/app, verify remaining data.
• If you’re using Zetsim, review the plan details for duration and data amount at purchase time.

Tip: if you’re traveling with heavy map usage, hotspot, or video calls, you’ll burn through data much faster than expected.

Reset options (use carefully): what to reset and when

If you’ve tried the basics and your eSIM still won’t work, resets can help—but they’re a bigger step. Use them in this order:

1) Reset network settings (recommended reset)

This clears saved networks and cellular configuration quirks. You’ll need to reconnect to Wi‑Fi afterward.

2) Avoid deleting the eSIM unless you must

Deleting an eSIM can remove the profile. Re-adding may require the original QR code or activation details. If you’re already traveling and don’t have those handy, deleting is risky.

If you do delete the eSIM, make sure you can reinstall it (QR code accessible, stable Wi‑Fi available) before you tap “Remove.”

FAQ: eSIM not working

Get your eSIM working (and keep it working)

If you remember only one thing: most eSIM failures are settings issues, not hardware failures. Pick the right data line, enable roaming on the right line if required, refresh network registration, and test without VPN. That solves the majority of cases.

External references: Apple Support · Google Support