I use Apple Pay with Face ID enabled, but after resetting my iPhone's settings, the phone started asking for my passcode whenever I unlock it. Previously, Face ID handled the normal unlock without requiring a passcode each time. In Settings, the relevant option appears unavailable or grayed out. Is there a way to restore Face ID unlocking without disabling Apple Pay?
3 Answers
Check Settings → Face ID & Passcode and make sure Face ID is enabled for iPhone Unlock and contactless payments. Also verify that the side-button double-click option for Wallet is enabled if you want to launch Apple Pay that way.
If Face ID is failing consistently after the settings reset, try setting up Face ID again and confirm that the phone isn’t restarting or entering a security state. iOS will always require the passcode in certain situations, but it should use Face ID for ordinary unlocks once everything is configured correctly.
Apple Pay itself doesn’t require your passcode every time you unlock the phone. Face ID should normally handle the unlock, while iOS may occasionally require the passcode for security—for example, after a restart or several days without entering it. A passcode can’t be removed entirely while using Face ID and Apple Pay.

I normally unlock with Face ID and use Apple Pay that way too. The passcode is only requested occasionally, roughly every few days, which is expected behavior.