Every Bluetooth device has a unique 48 bit MAC address. It's usually written as 6 hexadecimal bytes separated by colons. However, many user interfaces omit the colons when the MAC address needs to be entered into systems. All devices, apart from iOS, can see a sending device's Bluetooth MAC address.
What is Bluetooth Address (BD_ADDR)
Do Bluetooth Devices have MAC address with the same specification as the MAC addresses of the Ethernet and Wi-Fi Network cards?
Testing if a Beacon is Working
Bluetooth and Wi-Fi MAC Address Based Crowd Data Collection and Monitoring: Benefits, Challenges and Enhancement
Tracking Bluetooth Devices Without Using MAC Addresses