The safest way to update credit card information on a website is to log in to the secure portion of the site, edit the billing information, and then log out, as directed by Norton.com. The important thing is to ensure the site is using safety measures, such as SSL certificates.
It is important to enter credit card information only to websites using a secure server with an SSL certificate to encrypt sensitive information sent over the Internet. SSL certificates ensure that only the intended recipient can receive and read the information, cautions SSLShopper.com. Senders can determine whether a site is using an SSL certificate by the presence of an “s” at the end of the “http" string that precedes an Internet address, explains InstantSSL.com. This is sometimes only obvious after clicking on a graphic lock beside the website address to view the security certificate, notes CreditCards.com.
Senders should also use an encryption service if they send private data by email, advises AZCentral. Sites such as SendInc.com use military-grade encryption and delete messages from the recipients' servers after seven days.