(05 Jan 2014, 6:19 pm)ADLEnviro wrote catsfast101 - andreos1 has explained that as I would have but I will add a bit more to the above quote.
You need to remember that a Transfare is for use between two modes of transport, bus to metro, metro to ferry, ferry to bus are all fine, bus to bus isn't valid.
So on the 20 heading out of Sunderland towards Durham.
At Interchange you can board with a transfare from the metro and its valid to alight at any stop before the County Boundary at East Rainton.
You can buy a transfare for change onto the metro at University.
At Royal Courts you can board with a transfare from the metro and its valid to alight at any stop before the County Boundary at East Rainton.
You can not buy a transfare as for the rest of the route it is not possible to transfer onto another mode of transport.
At all stops after Royal Courts to the County Boundry at East Rainton you can alight but can not board or buy a transfare due to the service not passing any other modes of transport.
You still need to take into account the zone system for the fare and remember its different in the other direction.
Transfare really is a mine field.
It sounds very complicated, but I've get what you mean about royal courts now. How much are these things? let's say, Ryhope-Newcastle using 60/61/39 then Metro.