Firstly, don’t panic In many cases transactions turn out to be genuine and people simply don't remember. We suggest a quick double check to make sure it's not something you actually know about and agreed to. Is the transaction on your account? Check your account online. If you don't have online access you can easily sign up to manage your account online. Do you recognise the transaction or amount? Check receipts, it's easy to confuse similar amounts. If you have additional cardholders on your account, check to see if they authorised the transaction. Can you call the retailer / merchant? Most retailers/merchants are happy to help if a mistake has been made. You may find their contact details on your receipt or the internet.