- See also: School bond and tax elections in Oklahoma
Oklahoma is one of a handful of states that expresses its property tax cap limit using the mill rate formula over an mathematical formula. Oklahoma has a five mill limit that is protected by the Oklahoma Constitution. Oklahoma is different from other states as they use the five mill limit for issuing bonds, bond taxes, and exceeding the levy limit. Oklahoma requires a three-fifths (60%) super-majority vote to approve bond referendums while referendums involving the five mill limit only require a simple majority vote.
Section 5 of Article V of the Oklahoma Constitution is called Reservation of Powers to Voters of Counties and Districts - Manner of Exercising. It says that "The powers of the initiative and referendum reserved to the people by this Constitution for the State at large, are hereby further reserved to the legal voters of every county and district therein, as to all local legislation, or action, in the administration of county and district government in and for their respective counties and districts. The manner of exercising said powers shall be prescribed by general laws, except that Boards of County Commissioners may provide for the time of exercising the initiative and referendum powers as to local legislation in their respective counties and districts."
Section 5 of Article 5 goes on to say that as far as the number of signatures required to qualify a local ballot initiative, "The requisite number of petitioners for the invocation of the initiative and referendum in counties and districts shall bear twice, or double, the ratio to the whole number of legal voters in such county or district, as herein provided therefore in the State at large."