Why am I getting “Merchant_key invalid”?

Why am I getting “Merchant_key invalid”?

  • Ensure that you're using test (sandbox) credentials when testing in sandbox mode and live credentials when disabling test/sandbox mode.
  • Double check that the merchant ID and key on your Payfast account matches the one set on your plugin’s settings.
  • Check for spaces before and after the merchant key. Copy-pasting the merchant key can sometimes accidentaly include spaces.