I'm getting about 25 calls per day. (I started typing this when I had a call I didn't recognise and have had 2 more since I started typing - 02071 and 02073).
You could if you never wanted to hear from anybody in London 🙂
You may be the expert on many things, but London dialling code is 020, initially included 0207 and 0208, but now also 0203 and 0204. Although some of us use mobiles now.
Could you wildcard block 0207**