Login to your account at https://paybyphone.com/receipts with your phone number and current PIN.
Click the Profile button and locate the 'Click Here to change PIN' button
Forgot your PIN?
If you have forgotten your PIN, you can have it sent to you here.
Note: The system will lock you out for 20 minutes if you try the wrong account number/pin combination 3 times.
If you're unable to get into your account after 20 minutes, contact the PayByPhone support team by submitting a request through our Help Centre or emailing firstname.lastname@example.org