The registration under GST is Permanent Account Number (PAN) based and state-specific. GST Identification Number (GSTIN) is a 15-digit number and a certificate of registration, incorporating the GSTIN is made available to the applicant upon registration

• The first two digits of this number will represent the state code
• The next ten digits will be the PAN number of the taxpayer
• The thirteenth digit will be assigned based on the number of registrations within a state
• The fourteenth digit will be Z by default
• The last digit will be for check code

Structure of GSTIN

Each taxpayer is assigned a state-wise PAN-based 15 – digit Goods and Services Taxpayer Identification Number (GSTIN).

Registration under GST isn’t tax specific, which suggests that there’s single registration for all the taxes i.e. CGST, SGST/UTGST, IGST and cesses. A given PAN based legal entity would have one GSTIN per State, meaning a business entity having its branches in multiple States will need to take separate State wise registration for the branches in several States.

But within a State, an entity with different branches would have single registration wherein it can declare one place as principal place of business and other branches as additional place of business. However, a business entity having separate business verticals (as defined in section 2 (18) of the CGST Act, 2017) during a state may obtain separate registration for every of its business verticals.