There are two cases: - You have just given your credit card numbers on the Internet and have a doubt afterwards Check the email address of the sender or the domain name of the website where you entered your numbers. Most scammers pose as a known organisation (internet provider, mobile phone provider, parcel carrier, POST, tax office, CNS...) and then ask for your card. If the email address or the website address is different from the formats used by the organisation in question, block your payment methods and contact your bank. - You notice several suspicious payments on your bank account Try to remember any unusual trips, activities or payments you may have made on that date. If the amounts are numerous, similar and do not remind you of anything, then stop your card and inform your bank advisor.