Enter the email address and password you used to sign up with Buildbox then login.
In case you have forgotten your password, you may click the Forgot Password link shown below.
Then type in the email address that you used to sign up with Buildbox and click RECOVER PASSWORD button.
Once inside, go to the Billing tab.
Then click CANCEL.
Select your reason then click Cancel Account.
Once done it will take you to the confirmation page.