Just ask where he's driving from, or could he be staying in a hotel ?? I always ask on phone so where are you driving from and I also say if it's near me , is that work or home, one guy said  same town as me ( it's small) so I just said "sorry I hope you don't mind I'll decline " they just said " oh no , of course that's fine" they knew what I was getting at and at the time taking Incalls from another town but the place he was coming from was where I lived ? I had one guy guess where I was and kept calling me on his lunch break trying to make a booking I could see him out of my window ( he had no idea of the road just the estate ) but I guessed it was him so said goodbye and watched him put phone back in his pocket.......it's a cut through so lots people walk past, plus I haven't any face pics etc....but I'd prob decline I always think it's a guy I might know trying to find me out , that's why I like talking on the phone .....and most of the guys I see DONT want to see someone in their own town , in case you 'out' them you could be a nutter too !!!

I live in a city and the first 3 digits of the postcode apply to a huge area, literally a few square miles, I think.

Same here my pstcode is a massive area but some can b really small my mums is 10 houses

How about....asking for the full postcode as you need to check your driving/travelling times ( perfectly reasonable) and also , say you always get the area/ address first...to do your checks , he shouldn't mind and that could solve it for you ....or another one, " I have a booking earlier/later, or even your sisters birthday party that night so would need to jiggle things as you have to get home and changed etc first so will be doing a fair bit of driving ? Just ideas ignore if useless lol

I once saw someone who was in the flat opposite mine.I didn't realise until he was in the booking and he told me and pointed out his flat.I just made out I had only rented it for a couple of nights and as he wasn't a particular gem of a client that I was arsed to see again,I just ignored his calls when he tried to rebook.