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.
Builders who report a missing piece often find it in one of these places. Tick each one off as you look.
Look-alike colors in this set
These parts appear in this set in two colors that are easy to confuse. If you are one short in one color,
check whether it went in where the other color belongs. Each color has its own element ID in the parts list
at the back of the instructions.
Plate Round 1 x 1 with Solid StudRed ×10Trans-Red ×5Trans-Red is see-through: hold the piece up to a light.
Plate Round 1 x 1 with Solid StudWhite ×10Trans-Clear ×5Trans-Clear is see-through: hold the piece up to a light.
Plate Round 1 x 1 with Solid StudOrange ×10Trans-Orange ×5Trans-Orange is see-through: hold the piece up to a light.
Rock 1 x 1 Crystal 5 PointPearl GoldPart 30385Element 6174085 or 4516816×5
String, Bands and Reels
5 pieces
Chain 16L [21 Links]Dark Bluish GrayPart 60169Element 6258887 or 4516456×5
Gear Parts
2 pieces
Storage Bin, Dacta, Medium [New Style]BluePart 54187×1
Storage Bin Lid, Dacta [For New Style Trays]Trans-ClearPart 54190×1
Technic Axles
2 pieces
Technic Axle 3 with StudDark Bluish GrayPart 6587Element 6587199 or 6129590×2
Technic Connectors
2 pieces
Technic Axle and Pin Connector Angled #2 - 180°BlackPart 32034Element 6271869 or 4107783×2
Stickers
1 piece
Sticker Sheet for Set 45100-1[No Color/Any Color]Part 13101Element 6023521×1
Tools
1 piece
Brick and Axle Separator v2.0OrangePart 96874Element 6240515 or 4654448×1
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.