In message , at 11:52:34 on Sun, 6 Dec
2015, D A Stocks remarked:

Never seen a contactless transaction attempt declined.

I had to complete a contactless transaction as a chip & PIN transaction
once. The till operator told me this happens sometimes if an invalid
PIN attempt has been flagged for the previous transaction, as was
indeed the case.

I don't know if this would cause a subsequent contactless transaction
to fail if chip & PIN facilities aren't available.

If I remember, I'll try that tomorrow. All I need to do is put one of my
cards in an ATM and deliberately use the wrong PIN, then try to use it
on TfL. If it is rejected, then I can then try the same card in a C&P
enabled contactless terminal elsewhere.
--
Roland Perry