Just replied to your email sian, it's a Magpie Moth, (Eurrhypara hortulata).

Wingspan 24-28 mm.

This is one of the most familiar of the Pyralidae, with its yellowish body parts and black-and-white patterned wings.

It is very common in the southern half of Britain, becoming less so further north, and flies in June and July.

Little beauty, thanks for sharing this with us.
Divis.