Free Tool · CGST Rules 2017 · Instant Checksum

GSTIN Validator

Verify any GSTIN's 15-character format, state code, embedded PAN, entity number, and checksum digit instantly — before raising an invoice or entering a new supplier.

Enter GSTIN

Rule 9(1), CGST Rules 2017 · Section 25, CGST Act 20170/15

GSTIN Structure Reference

A GSTIN is always exactly 15 characters: SS PPPPPNNNNP E Z C

SS2-digit state/UT code (e.g. 27 = Maharashtra)

PPPPPNNNNP10-character PAN of the taxpayer

EEntity number (1–9, A–Z) — sequential for same PAN in a state

ZAlways the letter "Z" (default character)

CCheck digit computed by GSTN algorithm

Common State Codes

10Bihar

11Sikkim

12Arunachal Pradesh

13Nagaland

14Manipur

15Mizoram

16Tripura

17Meghalaya

18Assam

19West Bengal

20Jharkhand

21Odisha

22Chhattisgarh

23Madhya Pradesh

24Gujarat

25Daman & Diu (legacy)

26Dadra & Nagar Haveli

27Maharashtra

28Andhra Pradesh (legacy)

29Karnataka

Statutory Basis

GSTIN Format

GSTIN format is specified under Rule 9(1) of the CGST Rules, 2017 read with Section 25 of the CGST Act, 2017.

15-Character Structure

2-digit state code + 10-character PAN + 1-digit entity number + 'Z' + 1-character checksum (15 characters total).

State Codes

State codes are prescribed under the First Schedule to the CGST Act, 2017.

Checksum Algorithm

The checksum digit is computed using a modified Luhn algorithm prescribed by GSTN. This tool recomputes the check digit from the first 14 characters and validates it against the 15th character.

Need GST registration, filing, or compliance support?

Our CAs handle GST registration, monthly GSTR-1 and GSTR-3B filing, annual returns, and GST notices.

Talk to a CA →

Embed This Tool

<iframe src="https://harunraaj.com/tools/gstin-validator" width="100%" height="500" frameborder="0" title="GSTIN Validator"></iframe>