If you're wondering about a late fee for a book you returned on time, you should know that there are no late fees for items returned on or after July 1, 2024. Any late fees you're seeing would be from before this change.
If you returned the book when the library was closed, they'll check it in when they reopen, and you shouldn't be fined. It might take them a bit to update everything. If the book is still on your account after 24 hours, just contact the library where you returned it.
If you returned the item after it was 28 days overdue, you would have received a billed notice for the non-returned item. This notice would have included the cost of the item and any processing fees. However, after you returned the item, that fee would have been removed.
Related Page: Borrow & Return