Re-lock and unlock bootloader on the Nexus 5X for Android Pay A very recent change in Android Pay means I can no longer use it on my Nexus 5X that has an unlocked bootloader (http://www.androidcentral.com/android-pay-no-longer-works-if-you-unlock-your-bootloader-and-thats-good-thing).

I don't have root, and I don't actually use my unlocked bootloader at the moment, but I like that it's unlocked, because it gives me the option to get root later without wiping the device.

Is there any way to re-lock the bootloader, and then unlock it again without wiping?  Or is that impossible by design?
Currently, No.

Locking the bootloader actually requires a wipe as well now so you would have to back up your device and then restore after locking.

I was in the same scenario with my Nexus 6P and as I didn't need the bootloader unlocked any more i have locked it. I used a combination of adb backup, copying files manually off my device and the built in backup/restore functionality.