mould (US mold)

moult (US molt)

moustache (US mustache)

smoulder (US smolder, but boulder, shoulder)

tyre (US tire)

cypher (US cipher)

jewellery (US jewelry)

tranquillise (US tranqulize)

biassed (US biased)

clarinettist (US clarinetist)

aerogramme (US aerogram)

programme (US program)

epaulette (US epaulet)

omelette (US omelet)

disc (not a computer one, US disk)

sceptic (US skeptic)

flautist (US flutist)

gauge (US gage)

aeroplane (US airplane)

grey (US gray, but prey, obey)
plough (US plow) tonne (US ton)
baulk (US balk) draught (airflow, US draft)

axe (US ax)

annexe (US annex)

storey (of a building, US story)

storeys (of a building, US stories)

yoghurt or yoghourt (US yogurt)

sulphur (US sulfur)

cosy (US cozy)

Pouffe (US pouf)

manoeuvre (US maneuver)

cheque (US check)

groyne (hydraulic thing, US groin)

artefact (US artifact)

sheikh (US sheik)

pizazz (US pizzazz)
behove (US behoove)

herbs (US pronounced with no h sound)

connection (but sometimes UK connexion)

inflection (but sometimes UK inflexion)

jail (but sometimes UK gaol)