No automatic legal criteria exist. City status is a royal honour granted by the monarch on government advice.
Since 2000, competitive bids for royal occasions (Millennium, Golden/Platinum Jubilees, Queen's 90th). Recent winners: Southend-on-Sea, Colchester, Doncaster, Milton Keynes, Dunfermline, Bangor (NI), Douglas (IoM), Stanley (Falklands).
76 cities in the UK (55 England, 7 Scotland, 6 Wales, 5 NI, 3 Crown Dependencies). No new powers—purely ceremonial prestige.