Within Teamwork Spaces, you can update your billing contact information via your subscription settings
Click your profile image in the top right of your site and choose Subscription from the dropdown menu.
Scroll to the Contact Info subsection of your subscription settings and click the Change contact info button.
In the Update Billing Details area, you can update the contact email address and phone number in the Contact information subsection.
Click Update to save the changes to your billing contact information.
For more information, see: Updating Your Payment Details