Dial Assist is an iOS feature that automatically determines the correct international or local prefix when you make a phone call. While this is helpful for travelers, it can sometimes incorrectly format local numbers or conflict with specialized dialing patterns. This guide explains how to completely disable Dial Assist system-wide on an iPhone.
Prerequisites
No special privileges are required. This setting is available on all modern iOS versions.
Disable Dial Assist
Open Settings
Unlock your iPhone and open the Settings app from the home screen.
Navigate to Phone Settings
Scroll down through the main settings menu and tap on Phone.
Locate Dial Assist
Scroll down to the bottom of the Phone settings page until you find the Dial Assist option.
Toggle the Feature Off
Tap the toggle switch next to Dial Assist so that it turns gray, indicating the feature is now disabled.
Verify the Configuration
Once disabled, your iPhone will no longer automatically append country codes or prefixes to your dialed numbers. You must manually include the correct formatting (such as +1 for the US) when dialing international numbers from your contacts or the keypad.