Ever wonder what is that annoying pop up on the screen of your iPhone that says " Carrier Settings"?
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. You may receive notifications from time to time to install new carrier-settings updates.
Follow these instructions to update your carrier settings:
Note: Occasionally a carrier may release a mandatory update. This type of update will display only an OK button instead of an Update button, to let you know that the update was downloaded and installed.
If you need to know the version of the carrier settings your device has, tap Settings > General > About and look next to "Carrier".
Note: If you insert a new SIM or micro-SIM card into your iPhone or iPad, you'll need to download the carrier settings for the new carrier wirelessly by following these instructions.