I confirm Grubble's BE view, not that he needs it. Sinks are often deeper and hold more water, for obvious reasons. Sinks don't have to be in kitchens; they can be in utility rooms, for instance, anywhere that needs a large deep basin which can hold a lot of water, for reasons other than washing the person.In British English a sink is found in the kitchen and is used for washing dishes. A washbasin is found in the bathroom and is used for washing hands. There are no jugs involved!
A consequence of the influence of AmE, I presume.I agree with my BE colleagues above about the difference between sink and washbasin, and that washbasin, or basin, is current terminology.
But I have noticed increasingly that younger people refer to basins as sinks.