For every payment card you sign-up for, a new membership number is given to you. This is where the points you have earned from using your payment card are credited.
By combining all your accounts, you will have all your transactions in one, neat place. This will allow you to track and record all your points much better.
For any concerns or issues in merging your co-brand or payment cards to your Go Rewards Mobile app, please feel free to reach out to Go Rewards Customer Care by clicking this link.