You may upgrade or downgrade you plan at any time.
1. Click Settings, then Account Settings, then select the Billing & Plan Tab at the top of the page.
2. Scroll to the Change Plan options.
This user is currently in the Professional Plan. It will show the option for every other plan to switch to. You can click View Current Pricing to see the list of plans and the details for your current plan. Plan feature changes take place right away. Plan pricing will be in effect for your next billing period.