Add-on Credit Cards, sometimes referred as Supplementary or secondary Credit Cards are Credit Cards issued against a Credit Card held by the primary card holder. These are usually issued only to family members of the primary card holder upon application. Most banks issue them free of charge i.e. there are no additional annual fees on add-on credit cards. It us usually noticed that despite the benefits of add-on credit cards, most users don’t apply for them and miss out on benefits.