Andy wrote:
The only way I can see to test things off peak is to make a journey to
Zone A-D and see what the prepay deducts on the start of the return
journey (is it the minimum GBP1.00, or GBP1.30 (Zone A -3), 1.70(Zone B
- 3) or 2.00(Zone C or D - 3) to get me back to Zone2)

That is an interesting question actually, and one that I don't know the
answer to for now. I do however expect pre-pay users to be charged a
full £5.50 on entry to the system at Amersham, as this is the full D-1
single far on Oyster. Of course, currently it deducts £1.00 on entry
and the remainder on exit.

The problem with these new ideas is that the station staff are often
the last to know, and until we start to see patterns occurring, we can
only go by what we've been told.