Wired Accessories
iPhone Device & Theft Protection
Recommended
Use a setting that requires approval before new wired accessories can communicate with your iPhone.
What this setting does
Wired Accessories controls whether USB, Thunderbolt, and other compatible accessories can communicate with your iPhone. Restricting those connections while the device is locked reduces the opportunities available to someone who has physical possession of your iPhone and attempts to connect external hardware to it. Apple requires the device to be unlocked before accessories can communicate by default.
Important notes
Available choices depend on the iPhone model. On USB-C iPhones, Apple currently offers Always Ask, Ask for New Accessories, Automatically Allow When Unlocked, and Always Allow. On Lightning iPhones, the choices are Automatically Allow When Unlocked and Always Allow.
For USB-C iPhones, Ask for New Accessories is a good balance between security and convenience because each new accessory must be approved the first time it connects. Always Ask provides stricter protection by requiring approval every time.
Avoid Always Allow unless there is a specific operational reason to use it, because it permits accessories to connect without the normal locked-device restriction.
Storage accessories always require the iPhone to be unlocked before use regardless of this setting.