In message
, at
04:04:55 on Tue, 17 Apr 2012, Jack remarked:
If the card had capped at £12, and then the OP had then made a single
journey between any combination of zones 2-6, the total charge would
have been £13.40.

Based on the OP's information and all the available non-discounted
single fares, this is not what happened. The card never reached the
Z1-4 cap.

The Z1-4 cap is £10.80, so it *had* exceeded that, because before the
final £1.40 fare the total would have been £13.00

ps I'm now getting confused as to why the OP thinks the Z1-4 cap is £12.
--
Roland Perry