GSTIN Verification API

A GSTIN Verification API is used to validate GST numbers and retrieve registered business details such as business name, GST status, taxpayer type, and address. It helps businesses verify GST compliance and reduce errors during invoicing, onboarding, and financial transactions.

API Details

Request URL

POST

https://g99.in/api/public/gstin/search

Request Body Parameters

Type	Name	Optional	Description
String	gstin	Required	The Goods and Services Tax Identification Number assigned to a registered business under GST.
String	fyear	Required	The financial year associated with the GST filing, return, or verification data.

Sample Request Payload

request.json

{
  "gstin": "27ABCDE1234F2Z5",
  "fyear": "2025-2026"
}

Request Header Parameters

Type	Name	Value / Description	Optional
String	Content-Type	application/json	Required

Sample Code

request.php

$curl = curl_init();

curl_setopt_array($curl, array(
  CURLOPT_URL => 'https://g99.in/api/public/gstin/search',
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => '',
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 0,
  CURLOPT_FOLLOWLOCATION => true,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => 'POST',
  CURLOPT_POSTFIELDS =>'{
  "gstin": "27ABCDE1234F2Z5",
  "fyear": "2025-2026"
}',
  CURLOPT_HTTPHEADER => array(
    'Content-Type: application/json'
  ),
));

$response = curl_exec($curl);

curl_close($curl);
echo $response;

request.py

import requests
import json

url = "https://g99.in/api/public/gstin/search"

payload = json.dumps({
  "gstin": "27ABCDE1234F2Z5",
  "fyear": "2025-2026"
})
headers = {
  'Content-Type': 'application/json'
}

response = requests.request("POST", url, headers=headers, data=payload)

print(response.text)

request.cs

var client = new HttpClient();
var request = new HttpRequestMessage(HttpMethod.Post, "https://g99.in/api/public/gstin/search");
var content = new StringContent("{\r\n  \"gstin\": \"27ABCDE1234F2Z5\",\r\n  \"fyear\": \"2025-2026\"\r\n}", null, "application/json");
request.Content = content;
var response = await client.SendAsync(request);
response.EnsureSuccessStatusCode();
Console.WriteLine(await response.Content.ReadAsStringAsync());

Response

HTTP status code 200

Key	Type	Description
valid	Boolean	Indicates whether the GSTIN is valid and successfully verified.
active	Boolean	Shows whether the GST registration is currently active.
legalName	String	Registered legal name of the business or entity under GST.
tradeName	String	Business or trade name used commercially by the GST holder.
pan	String	Permanent Account Number (PAN) linked with the GSTIN.
constitution	String	Type of business constitution such as Proprietorship, Partnership, LLP, or Company.
nature	Array	Nature of business activities registered under GST.
type	String	Type or category of GST taxpayer registration.
registered	String	Date on which the GST registration was issued.
updated	String	Last updated date of the GST registration details.
expiry	String	Expiry or cancellation effective date of the GST registration, if applicable.
state	String	State in which the GST registration is registered.
stateCode	String	Official GST state code associated with the registration state.
center	String	Central GST jurisdiction name assigned to the taxpayer.
centerCode	String	Code of the assigned central GST jurisdiction.
jurisdictionCenter	Array	Central authority jurisdiction responsible for the GST registration.
jurisdictionState	Array	State authority jurisdiction responsible for the GST registration.
address	String	Registered business address associated with the GSTIN.
filings	Array	GST return filing status and filing-related information.
einvoiceEnabled	Boolean	Indicates whether e-Invoice generation is enabled for the GSTIN.

Sample Response

Sample response for valid document

response.json

{
  "valid": true,
  "active": true,
  "legalName": "SOFTNET PRIVATE LIMITED",
  "tradeName": "SOFTNET PRIVATE LIMITED",
  "pan": "AAGCG9742E",
  "constitution": "Private Limited Company",
  "nature": [
    "Retail Business",
    "Supplier of Services",
    "Wholesale Business"
  ],
  "type": "Regular",
  "registered": "28/09/2017",
  "updated": null,
  "expiry": null,
  "jurisdictionCenter": {
    "commissionerate": "DELHI-NORTH",
    "division": "Delhi",
    "range": "RANGE III",
    "state": "CBIC",
    "zone": "DELHI"
  },
  "jurisdictionState": {
    "circle": "Delhi",
    "division": "DELHI CENTRAL",
    "range": null,
    "state": "Delhi",
    "sector": null,
    "zone": "Central-III"
  },
  "address": "113, 1st cross street , Delhi 600034",
  "filings": [
    {
      "mode": "ONLINE",
      "filed": "15/04/2026",
      "type": "GSTR1",
      "period": "032026",
      "ack": null,
      "status": "Filed"
    }
  ],
  "einvoiceEnabled": false
}

Error Response

Parameter	Type	Description
status	Number	Unique error codes for different errors. Always available.
message	String	Error message describing the error. Always Available.
error	Boolean	True / False for different errors. Always available.

Error Codes

HTTP Status	Error Code	Error Message
400	4001	Malformed data or missing required parameter values.
400	4002	Invalid GSTIN Number.
503	5001	Request could not be processed. Please try again later.

Sample Error Response

response.json

{
  "message": "Malformed data or missing required parameter values.",
  "status": 4001,
  "error": True
}