iPhone 11 keeps telling me "Storage Full"

There is a difference between iPhone storage and iCloud storage, which is the only one that you can pay more for. See this, What's the difference between device storage and iCloud storage? - Apple Support

Check Settings>General>iPhone Storage and check.

carys227 Said:

"Iphone storage: Hello…my iPhone seems to keep telling me i’m full on storage but I only have about 350 pictures and videos in my camera roll and barely any extra apps. I also pay $3 a month for extra storage and it is still telling me I’m out of storage. Some of my friends have over 1,000 pictures and videos and still have enough storage and they don’t pay for extra. Why does my phone keep running out of storage? Is this a mistake?"

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Clearing Space:

Note your internal storage capacity. How much is it in total? Note that a top-resolution photo might be 2-4GB in size. So 1,000 would be 2-4GB. An iTunes movie might be 2-4GB. As you add more and more, more storage space is consumed. So, here is what to consider deleting...

What Space to Clear:

A. Clear Temporary Internet Files:

Clear your Temporary Internet Files(Cookies & Cache) of Safari:

• Cookies perform remembrance of certain site-entered data.
• Cache keeps a snapshot of the last time you visited a site.
• Go Here: Clear the History and Cookies from Safari on your iPhone, iPad, or iPod Touch - Apple Support

Also...



B. Clean TV and Music Libraries:

Remove all unneeded files from your TV and Music Libraries. Full-Movies take up 2-4GB typically, and a bunch of those would take up a load of storage, ideally. So, if you have any movies that are not needed, then delete them.

Also..

C. Clear "Other":

Clear the storages named "Other". It basically contains unnecessary files such as caches that are used for system ease of use - all of which gather over time: How to Clear "Other" in your iPhone's Storage - Use Backup - User Tips. Caches would be being used for remembrance of application use.