5. Credit card or bank transfer
Most accommodation providers require credit card details in order to guarantee your reservation. As such, we will send your credit card information directly to the accommodation at which your booking is made and we may verify (i.e. pre-authorise) your credit card as well. In order to safeguard and encrypt your credit card information when in transit to us, we use the "Secure Socket Layer (SSL)" technology for our services. If applicable and available, certain accommodation providers offer the opportunity for non-refundable reservations to pay directly to the accommodation provider during the reservation process by means of secure online payment (all to the extent offered and supported by your bank). Payment is safely processed through a third party payment processor and directly made from your bank account to the bank account of the accommodation provider. Booking.com does not make, accept or process any payment to or on behalf of the accommodation provider.

For certain (non-refundable) rates or special offers, please note that accommodation providers may require that payment is made upfront by wire transfer (if available) or by credit card, and therefore your credit card may be pre-authorised or charged (sometimes without any option for refund) upon reservation and confirmation of the booking. Please check the room details thoroughly for any such conditions prior to making your reservation.

In the event of credit card fraud or unauthorised use of your credit card by third parties, most banks and credit card companies bear the risk and cover all the charges resulting from such fraud or misuse, which may sometimes be subject to a deductible (usually set at EUR 50 (or the equivalent in your local currency)). In the event that your credit card company or bank charges the deductible from you because of unauthorised transactions resulting from a reservation made on our website, we will pay you this deductible, up to an aggregate amount of EUR 50 (or the equivalent in your local currency). In order to indemnify you, please make sure that you report this fraud to your credit card provider (in accordance with its reporting rules and procedures) and contact us immediately by email (customer.relations@booking.com). Please state 'credit card fraud' in the subject line of your email and provide us with evidence of the charged deductible (e.g. policy of the credit card company). This indemnification only applies to credit card reservations made using Booking.com's secure server and the unauthorised use of your credit card resulted through our default or negligence and through no fault of your own while using the secure server.

Source: http://www.booking.com/general.en-gb.html?...-and-conditions