There are only three things the UK uses Imperial units for: road signage (speed limits, distances, and vehicle dimension restrictions; and since 2016 all new dimension restriction signage has to be in dual-SI and Imperial units[1]), beer, and milk, the latter two of which are also sold in half-litre and litre measurements.
[1]: https://www.legislation.gov.uk/uksi/2016/362/pdfs/uksi_20160...