Well, 0113 is Leeds under the 1995 renumbering procedures and 0118 Reading under those in 2000. It makes one wonder whether someone is deliberately trying to appear that they're phoning from a 'legitimate' UK number when they could actually be phoning from god knows where.
Out of interest, I've recently had a number of calls from 01607 999 9999 (which I haven't answered because it looked dodgy. Now of course, this can't exist under UK numbering conventions, being a 12 digit number
Any ideas as to what the point of origins of these calls are, and what their purpose might be?