Wrong APN for your eSIM: how to check and restore it safely

Change the APN only when your eSIM has network signal but no data and HolySim has provided a specific APN. Compare the value character by character. An incorrect APN can disable mobile data.

HolySim advice: take a screenshot before making any change. It lets you return to the previous setup and shows support what was filled in automatically.

What an APN does

APN stands for Access Point Name. It is the network route that takes your mobile data traffic from the radio network to the internet. The provider may configure that route automatically or ask you to enter a short value manually.

An APN is not the same as Wi-Fi, a network name, or the password for your HolySim account. Never copy an APN from an arbitrary carrier simply because it operates at the same destination. Your eSIM may use a different technical partner.

Apple describes the APN as the network path for all cellular data connectivity and warns that incorrect values can cause you to lose the connection.

When to suspect the APN

An incorrect APN is most likely with this combination:

• the eSIM is switched on;
• the phone shows a network name and signal bars;
• 4G, LTE, or 5G may appear;
• Wi-Fi is switched off;
• data roaming is switched on;
• websites and apps receive no data.

If you see No Service or no signal bars, changing the APN is not the priority. Resolve the reception problem first. If the profile is still activating, wait before changing the APN until you have assessed the activation.

Find the correct value in your order

Only use the APN in the installation instructions for your order. Compare:

• the APN name;
• the username, if one is provided;
• the password, if one is provided;
• any instructions for hotspot or APN type.

Leave a field empty if the instructions do not mention it. internet, data, and the name of a local carrier are not safe guesses. Even one extra space can make a difference.

Cannot find the instructions anymore? Ask HolySim for the details and include your order number. In the meantime, do not change advanced values such as MCC, MNC, protocol, or authentication type.

Check the APN on iPhone

Open Settings > Cellular and tap the travel eSIM. Find Cellular Data Network. An alternative route is Cellular Data > Cellular Data Options > Cellular Data Network.

Make sure you are changing the settings for the travel eSIM, not your regular SIM. Fill in only the fields HolySim specifies. Then go back; iOS usually saves changes automatically. Switch airplane mode on for fifteen seconds and off again.

Cannot see Cellular Data Network? That can be normal. Apple states that the carrier can determine whether you can view or edit the APN. Contact support instead of installing a configuration profile from an unknown website.

Check the APN on Android

The general path is Settings > Network & internet > SIMs > your eSIM > Access Point Names. On Samsung, APN settings are usually under Connections > Mobile networks > Access Point Names.

Select the travel eSIM first if prompted. Open the existing profile, or add a new access point only when the HolySim instructions tell you to. Save it and select it using the radio button. Restart the mobile connection with airplane mode.

Android often displays many technical fields. Leave anything not mentioned in the instructions as Not set or at its existing default. Do not copy values from a forum, even when the phone and country match.

Restore the APN automatically

Did you change something yourself while data worked before? Use the reset option inside the APN screen rather than immediately performing a full network reset.

On iPhone, Reset Settings may be available under Cellular Data Network. Apple explains that this restores the default information from the carrier or configuration profile. On Android, the three-dot menu often contains Reset to default.

Take a screenshot first and keep the HolySim value. A software update or reset can return a manual APN to its default, which means you may need to enter it again later.

Test the change in isolation

Switch off Wi-Fi and temporarily disable any VPN. Open a new website. If it works, also check messaging, maps, and hotspot if your plan permits it.

If nothing works, recheck the selected mobile data line, data roaming, and remaining allowance. The APN is one possible cause, not the only one. Continue with the full troubleshooting process for no internet after installation.

Do not change several APN fields at once. If a support agent asks you to make an adjustment, apply exactly that change and test again.

APN after an update or reset

Apple notes that an iOS update can reset manual APN changes when no configuration profile is used. Android updates or a reset of mobile settings can also restore the access point.

If your eSIM is still visible after an update and you have signal but no data, compare the APN again. If the profile itself is missing, follow the guide for an eSIM missing after a reset.

When you need support

Contact support if the APN menu is missing even though a manual value is required, the correct APN cannot be saved, or data still does not work after all basic checks. Include screenshots of the APN screen, but obscure passwords if support does not need them.

Mention the phone model, software version, country, network name, and order number. HolySim can then check which APN belongs to your exact eSIM profile.

Sources and editorial review

The iPhone instructions and warnings were checked against Apple's guidance. Android paths differ by brand and software layer. APN values depend on the provider and plan, so this guide does not publish a universal value. Last substantively reviewed on July 15, 2026.