Hi,

I have a Z1-4 yearly travel card but had to visit High Barnet recently
and so bought an extension at West Finchley. But when I was in High
Barnet I found that the busses are classed as being in Zone 4 so I was
able to continue my journey to Barnet Hospital with no further charge.

Is there some odd historical reason why it's in Z5 for the tube but Z4
for the bus?

Thanks
Andy