In message , at 14:30:31 on Sun, 26 Feb
2012, Stephen Sprunk remarked:

The pumps had a sign suggesting that Electron card users put in at least
GBP 20 worth or else a larger amount of the balance on the associated
account would remain earmarked for a few days.

Sounds like they're authorizing the card for GBP 20, as discussed
elsewhere in this thread.

Not authorising, because that's "Electron" is a debit card on an account
which doesn't allow an overdraft. They will be deducting the £20
straight away, and allowing only up to £20 of fuel. If you buy less, it
sometimes takes a while for them to credit it you with the balance.
--
Roland Perry