Is the AutoPay set-up verification for Gold SIP a one time process?

No, you will have to individually verify the AutoPay set-up for each new Gold SIP. 

Note:

• Each AutoPay that you set-up for Gold SIP will be valid for a maximum of 30 years (default duration) from the date of set-up.
• You can delete your Gold SIP any time during this validity period of 30 years.
• You will have to set up a new Gold SIP if you want to extend the validity period of your AutoPay.

Learn more about setting up an AutoPay for Gold SIP.