Denver has a strong mayor/weak city council government. The mayor can approve or veto any ordinances or resolutions approved by the council, makes sure all contracts with the city are kept and performed, signs all bonds and contracts, is responsible for the city budget, and can appoint people to various city departments, organizations, and commissions. However, the council can override the mayor's veto with a nine out of thirteen member vote, and the city budget must be approved and can be changed by a simple majority vote of the council. The auditor checks all expenditures and may refuse to allow specific ones, usually based on financial reasons.