What is ARN in GST Registration? ARN stands for Application Reference Number. After conclusive proof of successful submission of the application and upload requisite documents online, the server generates the ARN. Does GST apply to all businesses? Yes, GST applies to all types of businesses, service providers, traders, and manufacturers. It extends to any dealers, bloggers, and writers, import-export business, all types of startups and companies, whether they are LLP's, proprietorships, partnerships, or private limited companies. Can I apply for GST Registration online? Yes, GST registration can be applied online. You can register your business through the official GST portal and scan and upload all the required documents. Once the application is received and acknowledged, a GSTIN (a unique 15 digit ID) will be generated and a temporary password and login will be sent.