On 19 Nov, 21:47, David of Broadway
wrote:
But capping is valid everywhere that PAYG is accepted, which includes
both TfL and non-TfL services - including a portion of the OP's route.

But you are perfectly entitled to use the cap to get to TTK. What you
can't do is use it to get a discount on the long distance fare, which
is what not getting off the train amounts to.

U