The Supply Closet is a returning location in the Ultimate Custom Night. It serves as the primary starting point for Lefty.
The Supply Closet appears the same like its original counterpart from the first game. However, there's no lamp hanging from above and the room appears slightly cramped in terms of the position of the objects surrounding the room.
This location is essential for keeping Lefty at bay when the Player makes him active for the duration of the night. If Lefty is shown deactivated in the room, the Player must be careful of maintaining both the Office's noise meter and temperature. However, when Lefty starts to change position, from staring at the camera to preparing to leave, it is advised to either lower down the meters that agitate Lefty or wound up the Global Music Box, which also keeps others such as Chica or the Puppet at bay.