Why does my spouse have to sign the indemnity agreement?
It is a standard underwriting requirement for sureties to require that a spouse personally guarantee the bond as well as yourself. Most personal assets are shared with your spouse. In the case of a claim, it ensures the personal assets used for underwriting are available to the surety. Otherwise, it is too easy in a claim situation to transfer assets to the spouse.
Exceptions can be made if there is a prenuptial agreement provided to the surety.