Princess Alexandra of Luxembourg made headlines this week after having lost her Visa credit card in Paris. But the Visa Infinite card isn't just any old card.

Princess Alexandra hasn't been reunited with her credit card yet, but there is certainly an incentive to get it back: The Visa Infinite credit card is the most exclusive product Visa has to offer. Read more about how Princess Alexandra's lost Visa Ininite credit card was discovered here.

Up until recently, the Visa Signature card was the highest tier credit card in the Visa family, one tier above the the standard Visa. It has since lost that position to the Visa Infinite, and to date, there are only handful of these elusive credit cards in existence.

The Visa Infinite credit card is comparable to the Platinum American and Express World Elite Mastercard in that only very wealthy customers have access to the service. Visa Infinite credit cards are instantly recognisable through their sleek black design.

While the Banque de Luxembourg could not tell us how many cards are currently out there, a representative for the bank told us that prospective owners must have at least a million in the bank and have to pay a fee of about €350 a year.

© Grand Ducal Court

Apart from having to be pretty wealthy and privileged to be able to afford a Visa Infinite credit card in the first place, the credit card affords the owner a lot of extra privileges and luxuries.

The Banque de Luxembourg promises its Visa Infinite holders personalised concierge services and access to "prestigious services". Owners can "get seats for a sold-out show", have "flowers delivered" or even "have someone else take care of day-to-day concerns" altogether.

It also offers the card holder travel and purchase insurance, as well as emergency medical cover. The Banque de Luxembourg Visa Infinite booklet also offers some handy advice to owners who might have lost their credit card:

© Banque de Luxembourg