You can cancel your membership at any time in My Account. To cancel, go to Membership in My Account.
Make sure the following selection is checked: No, I do not wish to renew. Please do not renew my account at the end of my Membership. I understand that I will no longer be able to bid at the end of my membership period. Choose this option and click the blue “Save Settings” button. Your membership will be cancelled immediately and you'll receive a confirmation code and an email.