Roland Perry wrote:
at 15:48:40 on Sat, 25 Feb 2012, Graham Nye remarked:

No, UK credit cards also have a magnetic stripe on the back, so they can
be swiped through a US retail terminal. You just have to sign on the
transaction, rather than use your PIN.

Only if, as above, the transaction is above the merchant's floor limit.
When using my UK credit card in the US I only needed to sign for some
transactions.

There's some over-simplification here. While I agree that some retailers
(especially high-margin ones like restaurants) may not require a
signature, there's a second floor limit above which they have to call
the credit card company. That limit seems to me to be much lower than
you'd get in the UK for a similar transaction verified by PIN.

Really? There's no concept of pre-authorizing the transaction, then
charging the customer the approved charge in two separate steps, both
performed at the retail terminal?

Jewelry stores don't call the credit card processor or bank if nothing
appears to be amiss. It's handled electronically.

The occasional machine, e.g. at gas stations, wanted to know my home
zip code (which, of course, I don't have) but I was able to pay in
the kiosk. (US gas stations need payment before dispensing fuel,
rather than afterwards, as in the UK.)

There's some over-generalisation here, it depends where you are in the
USA; some places need payment first, others don't. It depends a little
on the local demographic.

Actually, two gas stations at the same intersection can have different
policies.