Switch all auto features to ‘off’ and save big
When you take your iPhone on vacation with you, it can get very, very expensive. US data plans do not cover roaming outside of the US and users will be hit with hefty International Data Roaming charges.
The simplest way to avoid these charges is to leave your phone at home. If you must take it with you, turn off your data roaming. Downloading an email with a large picture, or, a 3 minutes YouTube video could cost you $40.
Turning off your 'Fetch New Data' feature will also prevent emails being automatically sent to your iPhone. Check for messages manually and only download what you really need to. When your phone is set to automatically check for new messages, this is done via International Roaming, so just imagine how your fees will skyrocket when you have your phone set to check for messages every five minutes.