If you forgot your iPhone passcode you can bypass the lock screen completely and reset the passcode by using iPhone recovery mode.
Now that the iPhone is in recovery mode, you must restore the device:
This will wipe all files, settings, and apps from the iPhone, including the passcode. When the restore is finished, the iPhone will be at the factory settings. At this point you can choose to start from scratch or to restore the iPhone from a backup.
This tip came from an iPhone repair shop, where it’s common for people to bring in a phone for fixing and then forget to provide the passcode.
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