For Library users who need to return books when the Issue Desks are closed there are "bookbins" in both the Main and Science Libraries. The Science Library bin is situated on the right as you enter the DMS Watson Building and is open until the Library closes at 22:30. In the Main Library, the bin is located immediately outside the doors leading to the Issue Desk, on the left-hand side. It can, theoretically, be used at any time of the day or night, although there is no Library security after 22:30. These bins are emptied every morning before 10:00. Fines from books due the day before, but returned after the Issue Desks have closed, are waived.
There are also bookbins at some of UCL's other sites, including the Institute of Archaeology and Cruciform, where they are situated just outside their respective libraries and only useable when these libraries are closed.
Bookbins should not be used for returning inter-library loans.