Overview
You might be considering upgrading the PHP version of your environment due to different reasons such as the existing version being EOL (End of life), and you are wondering what is the latest PHP version compatible with Kayako Classic.
Information
One can find the PHP versions supported by Kayako Classic in the Kayako Classic Server Configuration and System Requirements article. Note that only the PHP versions listed there have been fully tested to be compatible with Kayako Classic, and the article is updated as we receive further updates from the Engineering team.