Do Paid membership automatically downgrade when they expire?

[BCCF]

I know this is a totally new item that wasn't quoted on but it is a question about functionality more than anything.

When the site was originally built it was designed to have a popup message display for all users when their membership was getting close to expiring prompting users to renew their membership. However, we have started to notice that there are some familiar names in our paid users list that have been there for years but we haven't received payment to renew their membership that we know of.

When visiting their profile there is no indication of when they joined so we have no way of telling if our current paid affiliates are actually up-to-date on their payments unless we manually go thru the shop and match payments to usernames and this is often tricky because the user may have created an organizational account and paid for it with a personal credit card.

So, what we want to know is exactly how the site is setup to work so we can know if we do need to be manually tracking membership and manually removing their status once their membership expires.