How to update iOS version on iPhone 7 using iCloud account?

You cannot install just any version of iOS on an iPhone. Apple controls which iOS versions can be installed by digitally signing the software. You can normally install or restore an iOS version only while Apple is signing it for your device. Once Apple stops signing a particular version, you generally cannot install it, even if you have downloaded the IPSW firmware file.

For example, the iPhone 7 is not compatible with iOS 13.3.1 as a currently installable version unless Apple is signing that specific firmware for the device. Even though iOS 13.3.1 was released in the past, its availability for installation depends on Apple's signing status. The iPhone 7 also cannot be upgraded to iOS 16 or later because it does not meet the hardware compatibility requirements.

Apple continues to provide selected security updates for older devices that cannot run the latest major iOS versions. For example, as of 11 May 2026, Apple lists iOS 15.8.8 and iPadOS 15.8.8 for the following devices:

• iPhone 6s (all models)
• iPhone 7 (all models)
• iPhone SE (1st generation)
• iPad Air 2
• iPad mini (4th generation)
• iPod touch (7th generation)

These updates help address security vulnerabilities on older devices, even though they cannot upgrade to newer major iOS releases.

Important: A security update being listed on Apple's website does not mean that every older iOS version is available for installation. The device must support the update, and Apple must permit the installation through its signing process. The most reliable way to update is to use Settings → General → Software Update or an appropriate Mac or PC update method.

For official information, refer to Apple's support pages:

• About iOS 15.8.8 and iPadOS 15.8.8
• Apple security releases

khoeunseinghai wrote:

How to update version iPhone7 iOS 13.3.1

You can update an iPhone 7 to the latest version of iOS 15.

About iOS 15 Updates - Apple Support

Update your iPhone or iPad - Apple Support

Updating iOS: common issues and solutions – Apple Community

You cannot update an iPhone 7 to iOS 16, 17, 18, 26, or 27.

It sounds like your iPhone 7 is still running iOS 13.3.1 – which implies that you've been keeping it from automatically updating. If that iPhone is still running iOS 13.3.1 or something earlier, an "over the air" update might fail – and you might need to do the update to iOS 15.* with the aid of a Mac or a Windows PC.

Go to Settings > General > Software Update:

• What does it say there?

Your post was retitled, so not clear what the original tile was or the reference to using iCloud account that may have been added.

Think about getting an iphone that's not obsolescent. The 7 will not support many apps now.