A supplementary card, also called an additional or add-on card, is a card issued on an existing account to a second person nominated by the main cardholder. It is common with credit cards and charge cards. The supplementary card has its own number or card sequence and bears the user's name, but transactions are charged to the primary account and appear on the same statement.
The primary cardholder is normally responsible for all spending on supplementary cards, while the supplementary holder usually has no legal liability for the debt. Issuers let primary holders set separate spending limits, block categories or cancel the card at any time. Supplementary cards are used to give spouses, adult children or carers access to the account, and in business programmes resemble employee cards on a corporate card account. Effects on the supplementary holder's credit history vary, depending on whether the issuer reports the account to a credit reporting agency in their name.