For fresh applicants, one can apply for the GST ID online on the GST website. The GST id is a 15-digit number where the first 2 digits represent the state code and the next 10 digits will represent the PAN number of the business. The last 3 digits will be random alphanumeric variables. Here it needs to be remembered that each business location in a state will require a separate GST registration. So if you are headquartered in Mumbai and have branches in 12 other states then you will require a total of 13 GST registrations. While there are 3 separate GST viz. CGST, SGST and IGST, you only need to register once under GST. If you are already a taxpayer under service tax, excise duty, VAT or other subsumed indirect taxes, then you will be automatically migrated to GST and a new code allotted to you. The point is that the entire process is online and entirely seamless.