Some BMW 1 Series options at Tyres.co.uk include Michelin Pilot Sport 5 and Pirelli Cinturato C3 in 225/45 R17 94Y XL, a dealer all-round F40 1 Series fitment. Please check what your registration has approved for size, load index, speed rating, and run-flat construction prior to ordering.
For BMW 1 Series, you should check the Tyre Pressure Label on the door pillar (driver's side). It provides all the sizes and approved load, as well as the approved pressure, for your BMW. Check the handbook if you have optional wheels or staggered tyres, then verify against the tyre sidewall.
When replacing, the tyres on BMW 1 Series normally require only a matching axle pair and can be moved to the rear as per UK safety requirements. For BMW 1 Series xDrive, all wheels must have the same tread pattern, manufacturer and size, as well as similar tread depth, so all 4 must be replaced.