This guide explains how to get and use all File Cabinet Keys in Blue Prince, whether you are actively searching for them or unsure where they are used.

Mt. Holly is a mysterious manor full of surprises and secrets. Each room holds a clue or valuable items, revealed only through careful observation and analysis. The File Cabinet Keys are among the various secrets of the estate. It appears only at certain locations and opens specific drawers within the estate.
Players can find three File Cabinet Keys around the estate; each unlocks different cabinets and reveals useful clues and items. This guide explains how to get all the File Cabinet Keys and where to use them in Blue Prince.
Related: Blue Prince: How To Move the Foundation
File Cabinet Keys Location in Blue Prince

You will find clues about the first two File Cabinet Keys by draining the water in the Aquarium using the Pump Room. The third key becomes available later in the game. Here is how to get each key:
- File Cabinet Key #1: Located under the BBQ grill in the Patio. Use the Shovel to dig up the spot.
- File Cabinet Key #2: Found under the middle laundry machine in the Laundry Room. Dig the spot using the Shovel.
- File Cabinet Key #3: Found in the tunnel at the Grounds. However, you need to clear the crates first to reach the spot. You can clear the crates in the tunnels by downloading a data packet and conducting new experiments after unlocking the Satellite Dish. After clearing most of the crates, you will find a table on the right side, which holds the key on top.
Where To Use the File Cabinet Keys in Blue Prince

Much like finding the first and second File Cabinet Keys, the drained Aquarium also reveals a clue about where to use them. One of the drained fish tanks in the Aquarium contains a diorama of the Archives with an arrow pointing at its cabinets. File Cabinet Key #1 and #2 are used to open two drawers in a cabinet at the centre of the Archives, which contains an Upgrade Disk and documents.
The File Cabinet Key #3 can fit through the cabinet drawer at the Underground Reservoir area. You can use the key in a drawer located inside a hidden nook next to the mining tunnel, which becomes accessible by solving the rotating gear puzzles.
![Blue Prince Logo [Source: Raw Fury]](https://static.deltiasgaming.com/2025/04/Logo_Blue_Prince.png)
We provide the latest news and create guides for Blue Prince. Meanwhile, you can check out the following Blue Prince articles or catch us playing games on Twitch and YouTube: