All the business entities registering under GST will be provided a unique identification number known as GSTIN or GST Identification Number.
GSTIN (Goods and Services Tax Identification Number) format:-
The first 2 digits GSTIN will represent the state code.
01-Jammu and Kashmir, 02-Himachal Pradesh, 03-Punjab, 04-Chandigarh, 05-Uttarakhand, 06-Haryana, 07-Delhi, 08-Rajastan, 09-UP, 10-Bihar, 11-Sikkim, 12-Arunachal Pradesh, 13-Nagaland, 14-Manipur, 15-Mizoram, 16-Tripura, 17-Meghalaya, 18-Assam, 19-West Bengal, 20-Jharkhand, 21-Orrissa, 22-Chattisgarh, 23-MP, 24-Gujarat, 25-Daman and Diu, 26-Dadar and Nagar Haveli, 27-Maharashtra, 28-Andhra Pradesh, 29-Karnataka, 30-Goa, 31-Lakshadweep, 32-Kerala, 33-Tamil Nadu, 34-Puducherry and 35-Anadaman and Nicobar Islands.
The next 10 digits will be the PAN number
13th Digit-It indicates the number of registrations as a business entity has within a state for the same PAN. It will be an alpha-numeric number (first 1-9 and then A-Z) and will be assigned on the basis of the number of registrations a legal entity (having the same PAN) has within one state.
For Example-
company XYZ registered in the same state for 7 times for different businesses. In such case, this digit will be printed as 7. Let us assume, the same company registered for around 12 times, then it should be represented as C (1-9 numeric and later on 10th registration be named as A and 11th as B and so on up to Z).
Business entity can register the GSTIN within a single state for the maximum of 35 times
14th digit would be alphabet Z by default. It has been been kept for future use.
15th Digit-The last digit will be a check code which will be used for detection of errors.