The homestead exemption is a tax break on an owner's primary residence. In Georgia, the deadline to apply is typically April 1. Failure to apply by that date prevents you from taking advantage of the homestead exemption for that calendar year. Find your county below for more information, and if you live in a city municipality, there may be additional requirements.
https://taxcommissioner.dekalbcountyga.gov/TaxCommissioner/homesteadOnlineApp/TChomesteadOnline.asp (Online search - not a form)
Atlanta - If the property is in the City of Atlanta, when you apply for the Homestead Exemption in DeKalb County, it will automatically place an application for the City of Atlanta.