Business PayBill

Make business-to-business payments between PayBill accounts using M-Pesa by initiating payment requests and handling asynchronous result notifications.

User Stories

• As a fintech product owner, I want to programmatically initiate B2B payments so that suppliers receive funds immediately after approval.
• As an integrations developer, I want a simple client and clear webhook callbacks so I can implement reliable end-to-end flows with minimal boilerplate.
• As a billing operations engineer, I want result and timeout notifications with acknowledgements so I can reconcile transactions and trigger retries or alerts when needed.
• As a reseller partner, I want a tested SDK and examples so I can onboard quickly and reduce integration defects.

Parameters Definition

Parameter	Type	Description
Initiatorrequired str	String	M-Pesa API operator username (must be pre-approved by Safaricom).
SecurityCredentialrequired str	String	Encrypted security credential of the initiator (base64 encoded).
Amountrequired int	Integer	Transaction amount to be transferred between accounts.
PartyArequired int	Integer	Shortcode from which money is deducted for the payment.
PartyBrequired int	Integer	Shortcode to which money is credited.
AccountReferencerequired str	String	Account number associated with the payment.
Requester str	String	Consumer's mobile number (optional).
Remarksrequired str	String	Additional transaction information (maximum 100 characters).
QueueTimeOutURLrequired str	String	HTTPS endpoint that will receive timeout notifications.
ResultURLrequired str	String	HTTPS endpoint that will receive result notifications.
CommandID str	String	Command ID for the transaction (default: 'BusinessPayBill').
SenderIdentifierType int	Integer	Identifier type for sender (default: 4 for shortcode).
RecieverIdentifierType int	Integer	Identifier type for receiver (default: 4 for shortcode).

Response Schema

BusinessPayBillResponse — the synchronous acknowledgement returned by client.b2b.paybill(...)

Parameter	Type	Description
OriginatorConversationIDrequired str | null	String	Unique ID for the request message.
ConversationIDrequired str | null	String	Unique ID for the transaction.
ResponseCoderequired str	String	Status code of the request. 0 means success.
ResponseDescriptionrequired str	String	Status message describing the request outcome.

Overview

Business PayBill enables businesses to make payments between PayBill accounts. It's an asynchronous operation with callbacks for results and timeouts.

💡Implementation Options

• Use the MpesaClient facade for simple and safe integration: it manages authentication, header injection and returns typed Pydantic models.
• Use the Direct API (BusinessPayBill service + TokenManager + HttpClient) if you need full control over request/response handling, middleware, or custom error behaviors.
• Both are available as sync and async variants (MpesaClient/AsyncMpesaClient, BusinessPayBill/AsyncBusinessPayBill) — reach for async when calling from inside an async web framework, or when sending several PayBill payments concurrently.

💡Why use MpesaClient

The facade handles token retrieval and attaches Authorization headers so you can call high-level operations like initiating Business PayBill payments with minimal boilerplate.

Quick Setup (Sync)

Python

# Example: initiate Business PayBill payment using the high-level client
from mpesakit import MpesaClient

client = MpesaClient(consumer_key="...", consumer_secret="...", environment="sandbox")

resp = client.b2b.paybill(
  initiator="API_Username",
  security_credential="encrypted_credential",
  amount=239,
  party_a=123456,
  party_b=654321,
  account_reference="353353",
  requester="254700000000",
  remarks="Payment for services",
  result_url="https://your.example/result",
  queue_timeout_url="https://your.example/timeout"
)

if resp.is_successful:
  print("Business PayBill payment initiated successfully")
else:
  print("Business PayBill payment failed:", resp.ResponseDescription)

💡Notes

• The facade returns typed Pydantic models (e.g., BusinessPayBillResponse) for ergonomic access to fields and helpers like is_successful.
• Authentication tokens are handled transparently by the client.

Quick Setup (Async)

Python

import asyncio
from mpesakit import AsyncMpesaClient

async def main():
  async with AsyncMpesaClient(
      consumer_key="...", consumer_secret="...", environment="sandbox"
  ) as client:
      resp = await client.b2b.paybill(
          initiator="API_Username",
          security_credential="encrypted_credential",
          amount=239,
          party_a=123456,
          party_b=654321,
          account_reference="353353",
          requester="254700000000",
          remarks="Payment for services",
          result_url="https://your.example/result",
          queue_timeout_url="https://your.example/timeout"
      )

      if resp.is_successful:
          print("Business PayBill payment initiated successfully")
      else:
          print("Business PayBill payment failed:", resp.ResponseDescription)

asyncio.run(main())

⚠️Manual lifecycle (without the context manager)

In a long-lived service (e.g. AsyncMpesaClient wired up as a FastAPI dependency), construct it once at startup and call await client.aclose() on shutdown instead of opening a new async with block per request.

Webhook Handling (Result & Timeout)

The callback is an inbound HTTP POST from Safaricom to your ResultURL/QueueTimeOutURL — it isn't tied to whether the original request was sent via the sync or async client. The FastAPI handler below stays framework-async regardless, and validates the payload directly against the SDK's response schemas.

Python

# Example: simple FastAPI endpoints for Business PayBill Result and Timeout
from fastapi import FastAPI, Request, HTTPException
from mpesakit.business_paybill import BusinessPayBillResultCallback, BusinessPayBillResultCallbackResponse, BusinessPayBillTimeoutCallback, BusinessPayBillTimeoutCallbackResponse
from mpesakit.security.ip_whitelist import is_mpesa_ip_allowed

app = FastAPI()

@app.post("/b2b/paybill/result")
async def paybill_result(request: Request):
  payload = await request.json()
  caller_ip = (request.headers.get("x-forwarded-for") or request.client.host).split(",")[0].strip()
  if not is_mpesa_ip_allowed(caller_ip):
      raise HTTPException(status_code=403, detail="forbidden")

  data = BusinessPayBillResultCallback(**payload)  # will validate incoming fields
  # process the result (update database, notify user, etc.)
  ack = BusinessPayBillResultCallbackResponse()
  return ack.model_dump(mode="json")


@app.post("/b2b/paybill/timeout")
async def paybill_timeout(request: Request):
  payload = await request.json()
  caller_ip = (request.headers.get("x-forwarded-for") or request.client.host).split(",")[0].strip()
  if not is_mpesa_ip_allowed(caller_ip):
      raise HTTPException(status_code=403, detail="forbidden")

  data = BusinessPayBillTimeoutCallback(**payload)  # will validate incoming fields
  # process timeout notification (log, retry logic, etc.)
  ack = BusinessPayBillTimeoutCallbackResponse()
  return ack.model_dump(mode="json")

💡Important behavior

• Result and timeout endpoints should return acknowledgements (ResultCode 0). This confirms receipt to Safaricom.
• Process the actual Business PayBill result asynchronously based on the data in the result callback.

Result Callback Schema

BusinessPayBillResultCallback — posted to ResultURL once the payment completes

Parameter	Type	Description
Result.ResultTyperequired int	Integer	0 = success, 1 = failure.
Result.ResultCoderequired int | str	Integer/String	0 indicates the payment succeeded; any other value is a failure code.
Result.ResultDescrequired str	String	Human readable result description.
Result.OriginatorConversationIDrequired str	String	Matches the OriginatorConversationID from the initial request.
Result.ConversationIDrequired str	String	Matches the ConversationID from the initial acknowledgement.
Result.TransactionID str | null	String	M-Pesa transaction ID for the payment, when successful.
Result.ResultParameters.ResultParameter list[{Key, Value}]	Array	Transaction details, e.g. DebitAccountBalance, Amount, DebitPartyAffectedAccountBalance, TransCompletedTime, DebitPartyCharges, ReceiverPartyPublicName, Currency, InitiatorAccountCurrentBalance.
Result.ReferenceData.ReferenceItem list[{Key, Value}]	Array	Reference items, e.g. BillReferenceNumber, QueueTimeoutURL.

Timeout Callback Schema

BusinessPayBillTimeoutCallback — posted to QueueTimeOutURL if the payment doesn't complete in time

Uses the same Result shape as the Result Callback Schema above (it's the same BusinessPayBillResultMetadata model), just delivered to QueueTimeOutURL instead of ResultURL, typically with a non-zero ResultCode and without TransactionID/ResultParameters.

Callback Acknowledgement Schemas

What your webhook handler should return to Safaricom

Parameter	Type	Description
ResultCode int | str	Integer/String	Defaults to 0. Used by BusinessPayBillResultCallbackResponse and BusinessPayBillTimeoutCallbackResponse — the typed models to return from your /result and /timeout handlers respectively.
ResultDesc str	String	Defaults to 'Callback received successfully.' (result) or 'Timeout notification received successfully.' (timeout).

Responses & Helpers

Example Business PayBill Success Response

{
  "OriginatorConversationID": "5118-111210482-1",
  "ConversationID": "AG_20230420_2010759fd5662ef6d054",
  "ResponseCode": "0",
  "ResponseDescription": "Accept the service request successfully."
}

💡Response Handling

• BusinessPayBillResponse provides is_successful which normalizes success checks. Available identically on responses from the sync and async clients.
• The SDK normalizes minor provider response typos (e.g., 'OriginatorCoversationID') so fields are accessible reliably.

Error Handling

Python

# Handle errors when calling the service
try:
  resp = client.b2b.paybill(...)
except Exception as exc:
  # The underlying HTTP client may raise exceptions on network errors; log and retry as appropriate
  print("Business PayBill payment failed:", exc)

💡Notes

• HTTP or network errors raised by the HttpClient bubble up; wrap calls in try/except (sync) or around the awaited call (async) for robust production behavior.
• Tests exercise error flows to ensure exceptions propagate when the HTTP client fails, for both client variants.

Testing & Expected Behaviors

• Business PayBill:

  • The service posts to /mpesa/b2b/v1/paymentrequest with Authorization header set via TokenManager (or AsyncTokenManager).
  • Responses are returned as BusinessPayBillResponse instances, whether awaited from the async client or returned directly from the sync client.
  • The implementation tolerates a common provider typo ("OriginatorCoversationID") and maps it to OriginatorConversationID.

• Validation:

  • Incoming payloads are validated against BusinessPayBillResultCallback and BusinessPayBillTimeoutCallback. Missing required fields or invalid formats will raise validation errors.
  • Use the provided response schemas for acknowledgements; invalid codes are rejected by the model validator.

Next Steps

💡What's Next?

• Implement robust webhook handlers for result and timeout notifications. Log and persist notifications to support reconciliation.
• Add observability and retry strategies around Business PayBill calls and webhook processing to handle transient failures.

Related Documentation

• 📡 Webhook Setup Guide - Best practices for building reliable endpoints
• 🏗️ Production Setup - Go-live checklist, security and monitoring