In addition to state rules and regulations included in the Oregon Revised Statutes and Secretary of State publications, initiative petitions in the City of Portland are also governed by provisions of the Portland City Code. The main distinguishing characteristics of City initiative petition requirements are:
- Initiative petitions may be placed only on regular election ballots - biennial statewide primary and general elections.
- When filing their prospective petition, petitioners must indicate the election date for which the initiative is intended.
- Prospective petitions must be filed within 2 years and 4 months of the intended election date.
- Initiative petitions require a number equal to or greater than 9 percent of the number of electors registered in the city on the date of the primary municipal election immediately preceding the date the prospective petition is filed. Until the May 2018 election, the required number of signatures to place an initiative on the ballot is 34,156.
- The signature requirement for petitions filed after May 15, 2018 and until May 19. 2020 is 37,638. This number represents 9 percent of the total registered voters at the May 15, 2018 Primary Election in the City of Portland.
- Chief Petitioners must be registered voters of the City.