C2B00011C2B / B2C resultM-Pesa error C2B00011: Invalid MSISDN (Reject)
This is a C2B / B2C result code — it applies to customer-to-business validation or business-to-customer disbursement flows.
What causes it
During C2B validation the payer's phone number (MSISDN) is considered invalid by your validation logic.
How to fix it
Return this reject code when the MSISDN is unrecognized, or accept if you do not need to validate the payer number.
How paylod handles this
paylod records and decodes every C2B and B2C result, and lets you test the flow without hosting your own validation and confirmation callbacks — so you spend less time on Daraja plumbing and edge-case result codes.
See the paylod M-Pesa API