The easiest way to tell is from the line stats on a router/modem that is able to display them. Failing that you'd have to locate your cabinet in the street, you can get the cabinet number from the BT wholesale checker and compare the design with this website:
https://kitz.co.uk/adsl/fttc-cabinets.htm
If you want to go the UniFi route, you'd need a HG612, USG, UniFi AP, switch and a cloudkey (optional).