What is GST Registration number or GSTIN? What is the structure of GSTIN?

GSTIN stands for Goods and Services Taxpayer Identification Number. It is unique identification number allotted to Dealer by respective state. The Goods and Services Tax Network (or GSTN) is a non-profit organization and will manage the entire IT system of the GST portal

Structure of GSTIN: 

It is 15 digit Alpha-Numeric Code.

1st 2 digit	Next 10 digit	Next 1 digit	Next 1 digit	Next 1 digit
State Code E.g. 27 for Maharashtra	PAN E.g. AAAAC01234Z	Entity Code E.g. “1” if Entity has taken registration for one business in a particular state	Blank This digit is reserved for future use, and as of now redundant. Presently, default digit used is “Z”	Check Digit This is also the same as PAN has, which is system check digit

  

Also Refer:

CIN or Corporate Identification Structure
http://knowledgekhan.blogspot.in/2017/01/how-to-read-and-understand-cin-or.html

TAN or Tax Deduction and Collection Account Number
http://knowledgekhan.blogspot.in/2017/01/what-is-tan-tax-deduction-and.html

PAN or Permanent Account Number Structure
http://knowledgekhan.blogspot.in/2017/01/what-is-pan-permanent-account-number.html

STC or Service Tax Registration Number 
http://knowledgekhan.blogspot.in/2017/01/what-is-service-tax-registration-number.html  

Excise Registration Number
http://knowledgekhan.blogspot.in/2017/01/what-is-excise-registration-number-what_20.html 

VAT Registration Number

http://knowledgekhan.blogspot.in/2017/01/what-is-tin-or-taxpayer-identification.html