In case your iPhone has started using more Cellular Data than usual, it is possible that Photos App on your iPhone is using Cellular Data to upload Photos to iCloud Photo Library. You will find below the steps to Stop Photos App from using Cellular Data on iPhone.
Photos App Using Cellular Data On iPhone
iCloud Photo Library is an optional feature on iPhone that uploads photos and videos that you take to iCloud and makes them accessible across all Apple devices.
Once iCloud Photo Library is enabled on your device, all Photos and Videos that you take on your iPhone are automatically uploaded to your iCloud Photo Library, so that you can access your Photo library from any device, at any time and from anywhere.
In iOS 10 and earlier versions, Photos were set to sync with iCloud Photo Library only when your device was connected to a WiFi Network and the battery on your device was sufficiently charged.
However, in iOS 11 Apple has enhanced ON-THE-GO capability of the Photos App, allowing the Photos App on your iPhone to make use of both WiFi and Cellular Data to Sync and update the iCloud Photo Library.
Hence, if you are on a limited data plan, it is important to make sure that your iPhone is not using expensive Cellular Data to sync photos to iCloud Photo Library.
As you can imagine, high resolution images and 4K videos captured on an iPhone can quickly eat up your limited Cellular Data Plan and may lead to expensive overage charges.
Stop Photos App From Using Cellular Data On iPhone
Follow the steps below to stop iCloud Photo App from using Cellular Data on your iPhone.
1. Open Settings > scroll down and tap on Photos.
2. On the Photos screen, scroll down and tap on Cellular Data.
4. On the Cellular Data screen, disable Cellular Data usage by moving the toggle to OFF position.
After this setting, your iPhone will no longer use Cellular Data for updating the iCloud Photo Library.
Your iPhone will wait until it can connect to a WiFi Network, in order to make updates to your iCloud Photo Library.
Reduce Cellular Data Usage while Allowing Photos to Use Cellular Data
On certain occasions, you may come across the need to immediately update your iCloud Photo Library, even if this results in usage of your expensive cellular data.
In such cases, you can Reduce Cellular Data usage on your iPhone by switching the Unlimited Updates option to OFF Position.
1. Tap on Settings > Photos > Cellular Data.
2. On the Cellular Data screen, move the toggle next to Unlimited Updates to OFF position.
As you can see from above image, the description of this feature warns you about the possibility of excess data usage when this feature is enabled.