For most modern Dahua devices (Firmware v4.0 and newer), the serial number is used via the DMSS app to trigger an email-based reset. YouTube·Hik-Connect Hikvision

Before starting, you must locate your device's unique 15-character serial number:

If you have local access, right-click and go to Main Menu > Setting > Network > P2P . The SN is typically listed here alongside a QR code.

If you can access the device via a computer on the same network, tools like Dahua ConfigTool or SmartPSS will display the SN in the device list. Method 1: Reset Using the DMSS Mobile App (Recommended)