There is now a brand new billing system providing enormous flexibility. Click Options, and then Upgrades/Downgrades to access the new upgrade and downgrade functionality, and Options followed by Renewals to access the new renewals functionlity.
Using the Upgrades/Downgrades screen you can change your account to any level (Guest, Member, Full, Enhanced) at any time. You can also change your subscription period (up to 5 years). Increasing your subscription period gives you a 25% discount on your subscription fee for each additional year!
Using the Renewals screen you can update your credit card details, to ensure that your renewal is completed successfully. You can also manually renew using this screen at any time, or request that your account is not renewed at the end of your subscription until you use the 'manual renewal' button.