Twice a week I purchase split tickets from Horsham to Farringdon split at Gatwick. This week, when I have bought these tickets from the window at Horsham station, the ticket for the second leg of the journey has been from Gatwick to London Thameslink, not Gatwick to Farringdon despite me clearly stating Farringdon as the intended destination. Does this mean that a ticket purchased to London Thameslink is valid to use up to Farringdon? I haven't tested it on the barriers at Farringdon as I have gone through the assisted gate hoping to ask a member of staff about it (but don't get the chance and they never look at the ticket properly before letting me through), and earlier this week I walked to London Thameslink station to get back just in case the barrier at Farringdon would have rejected it. The cost of the ticket is the same as if Farringdon was the destination.