Transaction Reversal

Reverse a completed C2B M-Pesa transaction.

Usage

var reversal = new Reversal(gateway, initiatorPassword);

var payload = new ReversalPayload
{
    Initiator = "testapi",
    TransactionId = "OEI2AK4Q16",
    Amount = 1,
    ReceiverParty = 600978,
    ResultUrl = new Uri("https://mydomain.com/reversal/result"),
    QueueTimeOutUrl = new Uri("https://mydomain.com/reversal/timeout"),
    Remarks = "Reversal request"
};

var result = await reversal.ReverseTransactionAsync(payload);

if (result.IsSuccess)
{
    Console.WriteLine($"ConversationId: {result.Value!.ConversationId}");
}

The SDK automatically generates the SecurityCredential by encrypting initiatorPassword with the M-Pesa public key certificate (sandbox or production, based on your gateway config) using RSA PKCS#1 v1.5.

Payload Properties

Property	Type	Required	Description
Initiator	string	Yes	API username from the M-PESA portal
TransactionId	string	Yes	M-PESA receipt number to reverse
Amount	decimal	Yes	Amount to reverse
ReceiverParty	long	Yes	Organization shortcode
ResultUrl	Uri	No	URL for reversal result notification
QueueTimeOutUrl	Uri	No	URL for timeout notification
Remarks	string	No	Additional info (2–100 chars)

CommandId (TransactionReversal), RecieverIdentifierType (11), and SecurityCredential are set automatically.

Response Properties

Property	Description
OriginatorConversationId	Unique ID from M-PESA
ConversationId	Global unique ID for the request
ResponseCode	0 = success
ResponseDescription	Acknowledgment message