Have an iPhone 5? Update before Nov. 3 to keep key features

Apple is issuing an urgent warning for customers with older iPhones.

The tech company is encouraging people with the iPhone 5 to update to the latest available software before Nov. 3.

Apple said if users don't comply, several key functions like iCloud, App Store, email, web and other services will no longer work.

This is due to the GPS time rollover that began affecting GPS-enabled products from other manufacturers last April.

Apple is sending users full-screen alerts.