Rule out the usual hiding places first. If the piece really is gone, check the set piece by piece
and leave with the element ID LEGO asks for, or a link to buy the part.
Large Figure Torso Cover with Raised Belt [Plain]Dark TanPart 21561Element 6132841×1
Large Figure Torso Cover, Armour with 2 Chest Holes and Ball Joint SocketDark TanPart 90652Element 6133865×1
Plate 1 x 1Dark TanPart 3024Element 4549436 or 44970841 spare in the box×2
Technic Beam 1 x 2 Thick with Pin Hole and Axle HoleDark TanPart 60483Element 6344864 or 6170313×2
Dark Bluish Gray
15 pieces
Large Figure Hand, Fist with Axle Hole, 4 FingersDark Bluish GrayPart 93575Element 6099343×2
Large Figure Skeletal, Joint Extender [High Friction]Dark Bluish GrayPart 74261Element 6314448 or 6106472×4
Large Figure Skeletal, Limb with 2 Ball Joints, and Ball SocketDark Bluish GrayPart 90617Element 4622903×2
Launcher, Brick Special 1 x 4 Spring Shooter with Light Bluish Gray TopDark Bluish GrayPart 15400Element 6324200 or 6048898×1
Technic Axle 4 with StopDark Bluish GrayPart 87083Element 6083620 or 4560177×1
Technic Beam 1 x 3 with Ball Joint in MiddleDark Bluish GrayPart 98577Element 6001085×1
Technic Wedge Belt Wheel [aka Pulley]Dark Bluish GrayPart 4185Element 6321744 or 4587275×4
Dark Brown
8 pieces
Brick Curved 2 x 2 x 2/3Dark BrownPart 15068Element 6047037×2
Large Figure Foot, Type 2Dark BrownPart 90661Element 6133876×2
Plate Special 1 x 2 with Clips Horizontal [Open O Clips]Dark BrownPart 60470bElement 6167941×2
Pneumatic Hose Connector with Axle ConnectorDark BrownPart 99021Element 6265670 or 6167942×2
Light Bluish Gray
7 pieces
Large Figure Armor Plate, SmallLight Bluish GrayPart 28220Element 6168742×1
Large Figure Armor Plate, Small with Red Semi-circle PrintLight Bluish GrayPart 28220pr0002Element 6170315×1
Technic Axle 7Light Bluish GrayPart 44294Element 44294194 or 4211805×1
Technic Bush 1/2 Smooth with Axle Hole Semi-ReducedLight Bluish GrayPart 32123bElement 6271165 or 42115731 spare in the box×4
Tan
5 pieces
Technic Axle Pin without Friction Ridges LengthwiseTanPart 3749Element 4666579 or 4186017×3
Technic Pin 3/4TanPart 32002Element 6663097 or 60139381 spare in the box×2
Pearl Titanium
3 pieces
Large Figure Weapon Gun, Body with Hole on SidePearl TitaniumPart 24123Element 6135334×1
Technic Cylinder 4 x 4 with Pin Holes and Centre Bar, Closed Sides on BarPearl TitaniumPart 41531Element 6074417×1
Technic Pin Connector Round [Slotted]Pearl TitaniumPart 62462Element 6245501 or 6167943×1
Trans-Red
2 pieces
Projectile, Spring Shooter Ammunition 8L BarTrans-RedPart 15303Element 6287550 or 6054526×2
Flat Silver
1 piece
Hose, Ribbed 7mm D. 19L / 15.2cmFlat SilverPart 78c19Element 6170251×1
Nougat
1 piece
Large Figure Head Baze Malbus PrintNougatPart 27999Element 6164545×1
Reddish Brown
1 piece
Technic Axle 5 with StopReddish BrownPart 15462Element 6159763×1
[No Color/Any Color]
1 piece
Sticker Sheet for Set 75525-1[No Color/Any Color]Part 29476Element 6174332×1
Tick each piece as you find it, or mark it missing.
When a piece really is missing
Ask LEGO
LEGO takes requests for pieces missing from a new set through its customer service site. The form asks for
the set number and each piece's element ID, the number printed beside the piece in the parts list at the back
of the instructions. This checker lists both.
Mark a piece missing and your list links it to an eBay search for that part, which also covers pieces from
older or second-hand sets.
Keep a record
Copy or download your missing list (the CSV opens in any spreadsheet), or print the whole checklist and tick
pieces off on paper. Your marks stay in this browser, so you can check a big set over several sittings.