Combined Guarantee

A provision in a credit card agreement that applies when more than one person is responsible for any debts racked up.

This is different than a situation where a credit card with a sole account holder adds an additional person, like when a parent gets their kid an "emergency" card when they go away to college. These debts would still fall solely on the parent if the kid goes crazy one weekend and buys the entire dorm copies of As I Lay Dying (at least that's what they're telling the parents they bought...)

In a combined guarantee situation, both the parent and the kid would be responsible for the debt. A typical example of this might come up when a married couple share a credit card account.