How to Save Data on Your iPhone When Using a Travel eSIM

This is the single most impactful thing you can do. Low Data Mode tells your iPhone to reduce background activity across the board. That means no automatic app updates, no background iCloud syncing, lower streaming quality, and paused photo uploads. Everything you actually need still works; you just stop all the invisible stuff that eats through data.

How to enable it:

1. Go to Settings > Cellular (or Mobile Data)
2. Tap on your travel eSIM under the SIMs section
3. Tap Cellular Data Options (or Mobile Data Options)
4. Tap Data Mode
5. Select Low Data Mode

If you’re using dual SIM (your home SIM plus a travel eSIM), you can set Low Data Mode specifically for your travel eSIM line without affecting your home line.

For more detail, see Apple’s support page: Use Low Data Mode on your iPhone

This one catches a lot of people off guard. Wi-Fi Assist is a feature that automatically switches your iPhone to cellular data whenever your Wi-Fi connection is poor. Sounds helpful, right? It is, at home. But when you’re traveling and relying on a limited eSIM data plan, it can quietly burn through data without you realizing.

You’re sitting in a café with weak Wi-Fi, scrolling through Instagram, and your iPhone has silently switched to cellular data. That’s Wi-Fi Assist doing its thing. Turn it off.

How to disable it:

1. Go to Settings > Cellular (or Mobile Data)
2. Scroll all the way to the bottom of the page
3. Toggle Wi-Fi Assist off

For more information, see: Use Wi-Fi Assist on your iPhone

By default, your iPhone may back up to iCloud over cellular data. An iCloud backup can be hundreds of megabytes or even gigabytes. If this kicks in while you’re on your travel eSIM, it can wipe out your data plan in one go.

How to disable it:

1. Go to Settings > Cellular (or Mobile Data)
2. Scroll down and make sure iCloud Backup is toggled off

Alternatively:

1. Go to Settings > [Your Name] > iCloud > iCloud Backup
2. Turn off Back Up Over Cellular (or Back Up Over Mobile Data)

Your iPhone will still back up to iCloud when it’s on Wi-Fi, plugged in, and locked. That’s the ideal scenario, let it back up overnight at the hotel on Wi-Fi.

iCloud Photos is another big one. If you’re taking photos during your trip (and let’s be honest, you are), your iPhone may be trying to upload every single one of them to iCloud over cellular data. High-resolution photos and videos can eat through your data fast.

How to disable it:

1. Go to Settings > Photos
2. Under Mobile Data (or Cellular Data), toggle it off
3. Also turn off Unlimited Updates if it’s enabled

This way, your photos still sync only when you’re on Wi-Fi.

Background App Refresh lets apps update their content in the background. Social media apps, news apps, and email are all quietly using data even when you’re not looking at them.

How to manage it:

1. Go to Settings > General > Background App Refresh
2. Tap Background App Refresh at the top
3. Select Wi-Fi (or turn it Off entirely)

Setting it to Wi-Fi means apps can still refresh themselves, just when you’re connected to a Wi-Fi network.

The App Store can automatically download app updates over cellular data. A few app updates can easily add up to hundreds of megabytes.

How to disable it:

1. Go to Settings > App Store
2. Turn off App Updates under Automatic Downloads
3. Also turn off Automatic Downloads for Apps if it’s enabled

You can always update your apps manually when you’re back on Wi-Fi.

If you’re using dual SIM (your home SIM and a travel eSIM), there’s a setting called Allow Cellular Data Switching that lets your iPhone use your home SIM’s data when your travel eSIM has poor coverage. This sounds convenient, but it can trigger unexpected roaming charges on your home line.

How to disable it:

1. Go to Settings > Cellular (or Mobile Data)
2. Tap Cellular Data (or Mobile Data)
3. Turn off Allow Cellular Data Switching

While you’re at it, make sure data roaming is turned off on your home SIM. You’re using a travel eSIM to avoid roaming charges. Keep roaming off on your home line to be safe.

How to disable it:

1. Go to Settings > Cellular (or Mobile Data)
2. Tap on your home SIM under SIMs
3. Tap Cellular Data Options (or Mobile Data Options)
4. Turn off Data Roaming

Apps like WhatsApp, Telegram, and Signal automatically download photos, videos, and voice messages over cellular data. This can use a surprising amount of data, especially in active group chats.

WhatsApp: Go to Settings > Storage and Data > Media Auto-Download. Set photos, audio, video, and documents to Wi-Fi only.

Telegram: Go to Settings > Data and Storage > Automatic Media Download. Set When Using Mobile Data to low or disable media downloads.

Google Maps, Apple Maps, and other navigation apps can use a lot of data. Before you leave, download offline maps for your destination while you’re still on Wi-Fi. That way, you can navigate without using your eSIM data.

Google Maps: Search for your destination > Tap the location name > Tap the three dots > Download offline map

Apple Maps (iOS 26): Go to your profile in Apple Maps > Offline Maps > Download New Map

If you’ve updated to iOS 26, you may have noticed a new feature that Apple introduced: automatic travel eSIM switching. Here’s how it works: when your iPhone detects that you’ve left your home country, it can automatically activate a travel eSIM that you’ve previously installed and switch your data line to it. When you return home, it automatically switches back to your home SIM and turns off your travel eSIM.

On paper, this sounds great. And for many travelers, it works well. Your iPhone essentially manages the switch for you, so you don’t need to remember to toggle SIM lines manually when you land.

However, there’s a catch. There is currently no way to fully disable this automatic switching behavior in iOS 26. Apple has confirmed this is expected behavior and there is no toggle to turn it off. For most casual travelers, this isn’t an issue. But if you’re someone who uses multiple eSIMs across different countries, which many airline crew and frequent standby travelers do, this can cause problems.

Some users have reported that iOS 26 aggressively turns off their travel eSIM when it detects they’ve returned home, even when they want both lines to remain active. Others who live or work near country borders have experienced constant, unwanted switching. Apple’s engineering team has acknowledged the reports but, as of now, has not provided a way to opt out.

If this affects you, the best thing you can do is submit feedback directly to Apple at apple.com/feedback. The more people who report it, the more likely Apple is to add a disable option in a future update. In the meantime, you can always manually re-enable your eSIM lines via Settings > Cellular if they get switched off unexpectedly.

For more details on how this feature works, check out Apple’s support page: Use eSIM while traveling internationally with your iPhone

Here’s a quick recap of everything to check before your next trip:

• ✅ Low Data Mode — turned on for your travel eSIM
• ✅ Wi-Fi Assist — turned off
• ✅ iCloud Backup over cellular — turned off
• ✅ iCloud Photos on cellular — turned off
• ✅ Background App Refresh — set to Wi-Fi only
• ✅ Automatic App Updates — turned off
• ✅ Allow Cellular Data Switching — turned off
• ✅ Data Roaming on home SIM — turned off
• ✅ WhatsApp/Telegram media downloads — set to Wi-Fi only
• ✅ Offline maps — downloaded for your destination

These changes take less than five minutes and can save you a huge amount of data. Once you get back home, you can easily switch everything back.

At the end of the day, a travel eSIM is one of the easiest and most reliable ways to stay connected abroad, especially if you’re flying standby and your plans might change at any moment. But making a few small adjustments to your iPhone’s settings before you go can make the difference between your data lasting three days or lasting your entire trip.

If you’re looking for a travel eSIM that works in over 160 countries, has plans valid for a full year, and is designed with frequent travelers in mind, check out the StaffTraveler eSIM. It’s built by the same team behind the StaffTraveler app, and it’s become an essential part of our travel toolkit.

Safe travels, and may your data last as long as your trip does. ✈️