In this post I will show you how I converted my normal Codeigniter application into a multi-tenant system.(first step to a SaaS implementation) Note - This implementation is a separate DB multi-tenancy implementation. Lets say we have an up and running CI application name ci_app , with the directory structure like this ./application ./application/config ./application/...so many other important directories ./asset ./asset/js ./asset/images ./asset/css ./system ./index.php which is accessed through browser like http://localhost/ci_app So to implement the multi-tenant arch we are most concerned about the following files, and we will be editing them ./index.php ./application/config/config.php ./application/config/database.php And also we need to create a few new ones Create a tenant folder in your www root directory, lets say tenant_1 Cut the ./index.php from ci_app and paste it in tenant_1 directory Create a blank file config.php in tenant_1 directory ...