The reason you will receive this error is because you can not make payments to yourself through PayFast.
This will occur if you are using the same account that you have registered with on PayFast to receive payments, as the account that you are trying to make the payment from.
Most likely you are doing this to “test” the system.
If you want to test a transaction, please rather make use of the sandbox test environment.
here to test using the Sandbox.
If you do want to perform a live “test” you can use an email address that is not linked to the receiving account.