O.C.G.A. § 36-40-21

As used in this article, the term "municipal corporation" means a municipal corporation whose population shall be based on the current United States decennial census of 1980 or any future such census, the governing body of which has held at least six regular meetings within the 12 months preceding the execution of the certificate required by Code Section 36-40-22 and which for a period of one year has levied and collected an ad valorem tax on the real property in such municipal corporation or which has, for such one-year period, performed at least two of the following municipal activities and services:

(1) Furnished water service;

(2) Furnished sewerage service;

(3) Furnished garbage collection;

(4) Furnished police protection;

(5) Furnished fire protection;

(6) Assessed and collected business licenses; or