My wife just found this critter after receiving a sharp pain on her finger while delving into a box stored in our South Wales garage. Not certain if the spider was responsible, but it was in the right place at the right time. We've moved around a lot recently so this fella (or lady?) could come from London, Essex, Warwickshire, Oxford or South Wales. I thought it could be a false widow, but the markings on the back look a bit less extravagant than many of the false widow images I've seen online. Also, the affected finger doesn't seem too bad. Perhaps she wasn't bitten after all.
Many thanks for any help identifying the little scamp.
Yes, Steatoda grossa - but not really implicated in bites. Over the years very few people have presented this species of Steatoda as 'the spider that bit them' and almost all of those have been a bit speculative "well I found this spider later and believe it to be the culprit'.
Steatoda nobilis on the other hand ..... much more data to support this, though as Florin says a bit painful but people respond in different ways.