Maybe a Woodlouse Spider, (Dysdera crocata). Body size Female to 15 mm; male to 10 mm.
Appearance Distinctive, with prominent jaws, an absence of hairs, and a reddish carapace and legs, contrasting with a cream or grey-coloured abdomen (photo).
Habitat, range and season In and around buildings and under debris. Emerges from hiding places on nocturnal hunting excursions; woodlice are its main prey. Originally a native of southern Europe; now introduced to Japan, N & S America, S Africa, Australia and New Zealand. Adults throughout the year.
First recorded in the UK 1861.
Bite reports 'Held on to top of finger, had to be knocked off; the bite was like that of a bee sting, leaving a white spot on finger.'
'Similar to a nettle sting. The pain subsided after an hour, leaving a red mark and two tiny puncture marks which persisted for a couple of days.'