Unable to update my iPhone 6s Plus
I can’t do software Update my 6 S pluse phone
[Re-Titled by Moderator]
iPhone 6s Plus, iOS 11
I can’t do software Update my 6 S pluse phone
[Re-Titled by Moderator]
iPhone 6s Plus, iOS 11
What happens when you try??
If your details are correct and you're running iOS 11, then you may need to use a computer to do the update since you've neglected updates for so long.
Go to Settings > General > About
What does it say for iPhone Model and Software Version?
You need an iPhone 6s/6s Plus or newer in order to run iOS 15..
Supported iPhone models - Apple Support
If your iPhone is really an iPhone 6 Plus, then you cannot upgrade beyond iOS 12
If your Software Version is currently 12.5.5, then your phone is not a 6s Plus, it's a 6 Plus
In which case you will need a newer model iPhone in order to run newer iOS versions than 12
have you read thru this support article for updating?
Update your iPhone, iPad, or iPod touch - Apple Support
need more storage for update?
If you need more space for an update on your iPhone, iPad, or iPod touch - Apple Support
issues?
Updating iOS: common issues and solutions - Apple Community
video..
What happens when you try??
If your details are correct and you're running iOS 11, then you may need to use a computer to do the update since you've neglected updates for so long.
Go to Settings > General > About
What does it say for iPhone Model and Software Version?
You need an iPhone 6s/6s Plus or newer in order to run iOS 15..
Supported iPhone models - Apple Support
If your iPhone is really an iPhone 6 Plus, then you cannot upgrade beyond iOS 12
If your Software Version is currently 12.5.5, then your phone is not a 6s Plus, it's a 6 Plus
In which case you will need a newer model iPhone in order to run newer iOS versions than 12
have you read thru this support article for updating?
Update your iPhone, iPad, or iPod touch - Apple Support
need more storage for update?
If you need more space for an update on your iPhone, iPad, or iPod touch - Apple Support
issues?
Updating iOS: common issues and solutions - Apple Community
video..
Are you sure that you have a 6s Plus, and not a 6 Plus iPhone? The latter cannot be upgraded past iOS 12.5.5.
If you do have a 6s phone, the following could be the reasons that it will not upgrade:
Unable to update my iPhone 6s Plus