The Mii range kicks off with S and S A/C derivatives which come with black plastic door handles and mirrors, 14-inch steel wheels come without covers, and an MP3-compatible CD player with AUX-in port.
S A/C at £8,345 adds air con while both come with a 1.0-litre 58bhp three-cylinder petrol engine.
Ecomotive adds start/stop system and energy recovery and emits 96 g/km of CO2 and is priced at £9,180, while the SE kicks in at £9,275 for the 58bhp version, and £10,390 for the 74bhp DSG version.
Mii SE adds 14-inch alloy wheels, leather steering wheel, electric and heated door mirrors, and a gloss white dashboard panel.
The flagship of the range is the 1.0-litre 74bhp Sport which gets fog lights, dark tinted windows, 15-inch alloys and has lowered suspension.
Seat UK product manager, Simon Bradley, said: ‘Clearly the city car segment is a very price sensitive area and to have our great-looking new car available to order now at such exceptional RRPs means that we’re very confident about the Mii three-door’s potential in the UK.’