I always thought that the only condition for closing an account was a zero balance. I also ensured that no scheduled items were linked to it. Is there something else that i need to look at?

Also check whether it is mapped to an online account.

I figured it out, a little stupid on my part... it was a scheduled transfer that went into the account i wanted to close. So sadly, the schedules page only shows the originating account for a transfer and I had missed it when i scanned through them last night. I was able to close it after the schedule was updated to use a different account.