A private act charter applies only to the city or town with that specific charter. In other words, if your city or town is chartered under, say, Chapter 319, Private Acts of 1943, there’s only one city or town to which Chapter 319, Private Acts of 1943, applies: yours. The city or town next door to yours may also have a private act charter, but it will be chartered under, say, Chapter 27, Private Acts of 1901.
All cities with a private act charter were incorporated before 1953 when the constitution was amended to prohibit incorporating cities by special act. If a private act city wants to amend its charter, the city’s legislative delegation introduces the amendment in the General Assembly, and the city must ratify the new private act. The governing body of a private act city can play a major role in determining the municipal government’s form and structure. Its members can influence the legislature to make private act amendments, which may then be approved by a two-thirds vote of the governing body or by referendum. In a home rule city, charter amendments may be initiated by the governing body passing an ordinance, which is then submitted for referendum approval
Don’t get private act charters and general law charters mixed up. If you have a private act charter, none of the general law charters apply to your municipality. Your private act charter may provide for the mayor-aldermanic form of government, but the general law mayor aldermanic charter does not apply to your city.
There are general laws throughout Tennessee Code Annotated that apply to both private act and general law municipalities, but the general law charters apply only to municipalities that have those particular general law charters.