If you have exceeded your plan limits - database, users, or annual allotted crash volume - then you will be automatically upgraded to a plan which covers your usage.
You can see your usage on the Company page. If anything is in 'red' then it means that you're over your limit.
When this happens, you will get an email letting you know that your plan has changed. Your Account page and your next invoice will both reflect this upgrade.
This means that you'll have roughly a month before you are charged for a larger plan, giving you a window to get back into compliance and set your account back to its original setting.
Have users that don't need access any longer? Delete them! Don't use an old database anymore - feel free to retire it.
If you believe you shouldn't have been upgraded please contact us.
If you think that you need to upgrade to an Enterprise plan send us a note.
To learn more you can visit our pricing page.