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What Is This ‘Carrier Settings Update’ on My iPhone, iPad?

Oh God, what is this?

That's the first thought you might have when a notification appears on your iPhone or iPad prompting you to download a "Carrier Settings Update."

If you're like me, you'll shrug and tap the Update button (YOLO!). But others might be a little more wary, and want to know what the update is for and whether it's safe to download before taking any action.

Apple iPhone 5s
Getty Images
Apple iPhone 5s

Unfortunately, getting answers to these questions is much harder than it should be.

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Unlike major operating system updates, there isn't a lot of information or messaging about what carrier settings updates do, where they come from or how they impact your device. In fact, this whole story was borne out of a colleague's own frustration about the topic.

So I talked with Apple and all four major carriers — AT&T, T-Mobile, Sprint and Verizon — to get more information. One thing to note is that, according to the carriers, these updates are specific to Apple devices, namely the iPhone and cellular-connected iPads. Google and Microsoft also make carrier-related changes to their Android and Windows Phone devices, respectively, but they're folded into a more general software or maintenance update.

What is a carrier settings update?

As Apple describes it on its support site, "Carrier settings updates are small files that can include updates from Apple and your carrier to carrier-related settings, such as network, calling, cellular data, messaging, personal hotspot, and voicemail settings."

In other words, they handle anything related to how your device connects and communicates to your carrier's network and any related services.

The updates are largely used to add new features or enhance the performance. This can include adding support for upgrades made to a carrier's network or the rollout of new functionality like voice-over-LTE, which promises to deliver better-sounding voice calls.

Updates can also be used to fix a problem. For example, a carrier update was issued after a bug was found on the Verizon iPhone 5s that was causing the phone to use cellular data while connected to a Wi-Fi network.

Another instance where a carrier settings update may occur is when you swap out SIM cards. Let's say you've been using an unlocked iPhone on AT&T's network and decide to switch over to T-Mobile. Your iPhone will need to update its carrier settings so the device can work with the new provider. The same is true if you travel overseas and want to use a local SIM card to save money.

The update may happen automatically once you insert the new SIM card. But if not, you can go to Settings > General > About to start the process manually.

Since these updates tend to be smaller in size than major system upgrades, the update process should be faster, so you don't have to be offline for very long.

Who puts out the updates, and how are they delivered?

The updates can include changes from Apple or any of its official carrier partners, like AT&T or Verizon, or it can be a combination of both. (A couple of the wireless carriers I asked basically said, "It's an Apple thing — ask them.")

When one is available, you may receive a push notification on your iPhone or iPad, which you can download and install wirelessly. You may also get a message in iTunes the next time you connect your device to your computer via USB.

If you notice any network issues or problems using such features as voicemail, it's a good idea to check that you haven't missed a carrier settings update using the steps outlined above before contacting your provider.

Is there any way to see what the update is changing or fixing?

It's reasonable — smart, even — to want to know what's included in an update before downloading it to your iPhone or iPad.

Unfortunately, the companies don't make it easy to find out, if at all. It's not like a third-party app update, which often offers a change log to show you what's been added or fixed. In some cases, a provider might share details directly to the customer. Other times, the carrier might provide information on its website, though this usually involves digging through a myriad of support pages.

If all else fails, a Google search might lead to more specifics from an Apple or carrier-related user forum or site. But really, it would be nice if the parties involved spelled out the changes from the get-go, regardless of how big or small the update might be.

Are the updates safe to download? Is there any potential that the update might do more harm than good?

In general, the answer is, yes, they are safe to download. Apple's iOS mobile operating system is less prone (though not immune) to malware and viruses, compared with other platforms, like Android. Still, it's always good to keep an eye out for anything that seems fishy, like misspellings in the update message.

There is certainly the potential that an update might end up breaking something or negatively affecting your device's performance. We've seen this happen a few times with iOS updates. But this hasn't been a huge issue with carrier settings updates. If there is a problem, Apple and the carriers would assuredly issue a fix.

Do I have the option to skip an update or postpone it?

It varies. Some updates are mandatory, and the only option you'll see when the prompt comes up on the screen is "OK." Other times, you'll have the choice to proceed with the update or delay it by tapping the "Not Now" button.

What are the benefits of doing the update? Are there any downsides to waiting if possible?

Waiting to install an update, or just ignoring the alerts, probably won't cause any major problems.

But depending on what's being released with the update, the benefits could include more functionality, better data speeds or improved call quality. So you might be missing out on some features and a supposedly improved user experience.

After reading this, hopefully you'll feel better prepared to make a decision the next time a carrier settings update message pops up on your screen.

Updated with more information from Apple about the purpose of the carrier settings updates.

By Bonnie Cha, Re/code.net.

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