Thanks. Surely back then, Epsom was still in zone 9? That only got moved very very recently.
For Ewell West<->East. The cheapest paper ticket option is actually a split ticket (unsurprisingly splitting at Epsom). But PAYG is still marginally cheaper (15p difference for adult, and 5p difference for railcard). Since Epsom is within the Oyster zone, am I right in saying it’s perfectly legal to use Oyster for the sensible (via Epsom) route?