Annexation --- the increase in size of a municipality or village.

Detachment --- the decrease in size of a municipality or village.

Merger --- the merging of two municipalities or the merging of the unincorporated area of a township with a municipality that is adjacent to or that lies partly or wholly within the township.

Incorporation --- the process by which an unincorporated area becomes an incorporated municipality.

Boundary Adjustments --- the adjustment of the boundaries of two adjoining municipalities upon agreement by their legislative authorities.

Annexation by a municipal corporation of territory located in a township or in another municipality is governed by § 709 of the Ohio Revised Code. Annexation may be accomplished in three ways: (1) property owners in a territory adjoining a municipality petition the board of county commissioners to annex their area to the municipality, (2) a municipality through its council or other legislative authority petitions the board of county commissioners to annex an area contiguous to the municipality, or (3) a municipality passes an ordinance to the effect that it wants to be annexed by a contiguous municipality, an annexation commission is established, and an election is held. The first and most common method is described below.

Property owners who would like their property to become part of an adjoining municipality may present to the board of county commissioners a petition signed by a majority of property owners in the territory to be annexed. (§ 709.02) The board must file the petition with the county auditor to allow the public an opportunity to inspect it, and the petitioners’ agent must send written notices to both the municipality that would gain the property and the township(s) that would lose the property. Once the affected township(s) receives written notice, those who signed the petition for annexation may withdrawal their signatures within 20 days by sending written notice to the clerk of the county board of commissioners. (§ 709.03)

Within 60 to 90 days after the county auditor receives the annexation petition, the board of county commissioners must hold public hearings. Once the date and location of the hearings are set, the petitioners’ agent has seven days to deliver written notice of the hearings to the affected municipality and township(s). Following receipt of the notice, the municipality must pass an ordinance or resolution describing the services that will be provided to the territory if annexation is successful. The petitioners’ agent must also ensure that notice of the hearings is published in a widely available local newspaper, and the notice must appear once a week for four straight weeks during the period before the hearings begin. Thirty-one days or more before the hearings the board of county commissioners may send to the county engineer a description and map of the area to be annexed, and the county engineer may issue to the board a written report regarding the accuracy of the description and map. If the engineer decides to issue such a report, the commissioners are not bound by it. (§ 709.031)

At the public hearings before the county board of commissioners, any member of the public may oppose or support the annexation. The board may also hear testimony by one or more petition signers asserting that "fraud, duress, misrepresentation, or undue influence" was used to obtain their signatures. Where a majority of the board finds that such means were used to obtain a signature, the signature is struck from the annexation petition. If the petitioners’ agent consents, the board of commissioners may also entertain amendments to the annexation petition. In the event an amendment proposes enlargement of the area to be annexed, the commissioners are required to schedule an additional public hearing. (§ 709.032)

Within 90 days of the public hearings, the board of county commissioners issues an order granting or denying the petition for annexation. The board’s decision rests in part on whether the proper annexation procedures were followed, but the board is also required to find that the area to be annexed is not too large, that the map or plat of the area is accurate, and that annexation would serve the general good of the territory to be annexed. If the board of county commissioners denies annexation, it sends certified copies of the commission’s orders to the petitioners’ agent and to the clerk of the affected municipality. If the annexation is granted, however, the board enters all annexation-related orders in its journal and forwards a transcript of those orders and all maps and other related materials to the auditor or clerk of the affected municipality. (§ 709.033)

At least 60 days after the clerk or auditor receives these materials, he or she presents them to the council or other legislative authority, and the authority through resolution or ordinance either accepts or rejects the application for annexation. Rejection of the application effectively ends the annexation action. If, on the other hand, the application is accepted, then copies of all annexation-related materials are sent to the county auditor, the county recorder, and the secretary of state. The annexation becomes effective 30 days after passage of the ordinance accepting the application. (§ 709.04 - § 709.10)