Fare finder has no “avoiding zone 1” fare for this journey. Using contactless, if you go Redhill-Clapham Junction-pink reader-Southern to Watford Junction what can you expect to be charged?
The "avoiding zone 1" is the default. If you go via Victoria or London Bridge you pay more.
Peak £16.40
Off-peak £10.80
Is the fare via Shepherds Bush. No pink reader needed.
Peak £19.00
Off-peak £12.60
Is the fare via va Zone 1 changing between National Rail and London Underground at Blackfriars, London Bridge or Victoria (or Cannon Street, Charing Cross, Waterloo or Waterloo East)
One reason why a pink reader touch is not needed at Clapham Junction is due to the East Croydon to Watford Junction service.
A slightly cheaper fare is available changing at West Hampstead. However the default fare also applies for a change at St Pancras / Euston.
A further saving can be had by touching out / touching in at certain stations between Redhill and London Bridge, for example East Croydon.