If you get a new phone, you can reset your phone at: https://www.authy.com/phones/reset. Please note this does not happen on PayFast's website. This step may be necessary if you change smartphones, in which case your account will already be linked to a specific smartphone.
If you get a new mobile number, you will be required to uninstall the app on your smartphone, and re-install it in order to register the new number.
If you have lost your phone, and need access to our system, then you can contact our support staff on merchantsupport@payfast.co.za who will be able to assist you.