It's a Mottled Umber, a species whose disgraceful discrimination between the sexes formed the basis of my recent rallying call to feminists on the blog - click to remind yourselves here. This moth is around all winter and the males come to light regularly, as this one did. He's at the top end of the decorative scale. The wing pattern and colour varies and some are an almost uniform beige.
The trap itself was empty this morning and I may rely on the porch light for a while. But the extraordinarily mild nights are a temptation for putting out the full works, and there are reports of Saharan winds blowing unusual moths this way, so watch this space.