Generate IRN

base_url: https://firseinvoice.etranzactng.com/

Description: This endpoint generates an IRN (Invoice Reference Number) using three critical data points - the taxpayers’ internal invoicing system/ERP/accounting system (invoice number), FIRS-assigned credentials (service Id) and the exact date the invoice was issued in numeric format: YYYYMMDD. The business id is issued by the regulator. The IRN is unique for each transaction, ensures generated digital invoices are secure and traceable.

Sample Request

Request Parameters

Parameter	Type	Description	Required?
invoice_number	string	Taxpayer’s Invoice/transaction reference value (transaction id)	Yes
service_id	string	FIRS issued/assigned credential	Yes
issuance_date	date	Date invoice was issued	Yes
business_id	string	Unique alphanumeric ID generated when the business is registered on the e-invoicing platform. It allows the system recognize all invoices generated by the company	Yes

Sample Response

Response Parameters

Parameter	Type	Description	Required?
status	integer	HTTP status code	Yes
message	string	Description of http status code	Yes
data	object	A nested data object containing the primary Yes details of the response	Yes
irn	string	A unique tracking number assigned to each invoice.	Yes
execTime	integer	Time taken to process request (for metrics and performance tracking).	Yes
error	integer	Specific errors when request does not return a HTTP status of 200.	No

Sample Request

Request Parameters

POST {base_url}/api/v1/si/invoice/generate-irn

curl -X POST
  -H "X-API-Key: {{CLIENT_API_KEY}}"
  -H "X-API-Signature: {{HMAC_SHA256_SIGNATURE}}"
  -H "X-API-Timestamp: {{ISO_20022_TIMESTAMP}}"
  -H "Content-Type: application/json"
  -d '{
    "invoice_number": "INV285",
    "service_id": "47AT78FN",
    "issuance_date": "20250417",
    "business_id": "6f19a0f0-c8f3-4d2b-8a8b-1b2c45e89d0f"
  }
'

Sample Response

Sample Success Response

POST {base_url}/api/v1/si/invoice/generate-irn

{
 "status": 200,
 "message": "IRN generated successfully.", 
 "data": {
    "irn": "INV285-47AT78FN-20250417"
 },
 "execTime": 1.388868,
 "error": ""
}