In message , at 13:39:58 on Sun, 24 Nov 2013,
Phil remarked:
Contactless transactions inherently don't feature online authorisation
with the bank, because there isn't enough time.

When I use contactless payment in the local Co-op, the machine still
goes through the same calling acquirer, authorised messages it does when
I use my pin.

s/online/real time/

It'd be interesting to have some case studies of where a contactless
transaction wasn't in fact accepted less than a second after being
proffered.
--
Roland Perry