By Simon Gompertz Business Correspondent

You're in a foreign country, on holiday.

There are lots of things to pay for and shopping to be done.

But there's no need to worry because you've brought your credit card. Right?

No, wrong. What I found was that your credit card company might leave you in the lurch, just because you are overseas.

After a few days in France recently, shops started refusing my card as a form of payment.

Credit limit

The payment slips were returned to me politely with "Abandoned" typed neatly across the bottom.

I knew I had not exceeded my credit limit, so what was the problem?

The obvious fear was that someone was defrauding me and the card company by charging huge sums in my name.

In fact I discovered that my bank's sophisticated anti-fraud alarms had been triggered simply because I was trying to use the card in another country.

After frantic mobile phone calls back to the UK, the bank flagged up the problem on my account to try to ensure that I could use the card.

Protection

No-one underestimates the problem of credit card fraud.

The cost jumped 30% to �411m last year and a third of it involves the abuse of UK cards from overseas.

So the card companies are stepping up their protection systems.

They have complicated computer programmes in place, designed to spot unusual expenditure which might turn out to be fraud.

Unfortunately, the programmes aren't always right.

Inconvenienced

Insiders in the credit card industry admit that more cards are being blocked and more innocent users will be inconvenienced.

That is until new, secure cards come into use in a couple of years' time.

Like the French, we will need to key in a special identification number in the shop to prove that the cards we are using are genuine.

Until then, expect increasing confusion. Banks do not like to admit that they have blocked a customer's card unnecessarily.

Victims will probably be told that they are confusing a "referral" with a "refusal".

Warning

A referral involves the shop being asked to ring up to confirm that the cardholder is genuine.

But, in practice, most shops and businesses overseas don't understand the concept or can't be bothered to make the call.

What to do? Some banks are begining to recommend that customers warn them when they are going on holiday. Others say that warnings will not not make any difference.