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.
Brick Curved 4 x 1 Double, No StudsTan ×1Light Nougat ×2Tan is yellower and darker than Light Nougat.
Brick Curved Inverted 2 x 1Tan ×4Light Nougat ×2Tan is yellower and darker than Light Nougat.
Plate 1 x 2Tan ×2Light Nougat ×2Tan is yellower and darker than Light Nougat.
Plate Round 2 x 2 with Axle Hole Type 1 (+ Opening)Tan ×4Light Nougat ×11Tan is yellower and darker than Light Nougat.
Plate Special 1 x 2 Rounded with 2 Open StudsTan ×7Light Nougat ×8Tan is yellower and darker than Light Nougat.
Plate Special 1 x 3 with 2 Studs with Groove and Inside Stud Holder (Jumper)Tan ×2Light Nougat ×2Tan is yellower and darker than Light Nougat.
3 more look-alike pairs
Tile Special Round 2 x 2 with HoleTan ×2Light Nougat ×4Tan is yellower and darker than Light Nougat.
Technic Wedge Belt Wheel [aka Pulley]Light Bluish Gray ×4Flat Silver ×2Light Bluish Gray is lighter than Flat Silver.
Plate 2 x 2Black ×2Dark Bluish Gray ×6Black is darker than Dark Bluish Gray.
Hose Rigid 3mm D. 43LFlat SilverPart 75c43Element 6314440×1
Technic Wedge Belt Wheel [aka Pulley]Flat SilverPart 4185Element 6533241Also in Light Bluish Gray×2
Bright Pink
4 pieces
Brick 2 x 2Bright PinkPart 3003Element 4550359 or 4245307×1
Plate 1 x 1Bright PinkPart 3024Element 6031883 or 4599540×1
Plate Special 1 x 2 with 1 Stud with Groove and Inside Stud Holder (Jumper)Bright PinkPart 15573Element 6264994×1
Tile 2 x 2 with GrooveBright PinkPart 3068bElement 4615728×1
Bright Green
2 pieces
Plate 2 x 3 with 1 x 1 CutoutBright GreenPart 73831Element 6603088×1
Tile Round 1 x 1Bright GreenPart 98138Element 6353793×1
Dark Brown
2 pieces
Animal Body Part, Fin 2 x4 with HandleDark BrownPart 7511Element 6593254×2
Dark Tan
2 pieces
Technic Axle 4.5 with StopDark TanPart 7784Element 6569661×2
Trans-Clear
2 pieces
Dish 3 x 3 Inverted [Radar]Trans-ClearPart 43898Element 6507917 or 6244730×1
Rock 1 x 1 Jewel / Gem 24 FacetTrans-ClearPart 30153Element 6513976 or 6247798×1
Dark Pink
1 piece
Wool / YarnDark PinkPart 6900Element 6509764×1
Dark Turquoise
1 piece
Bracket 1 x 2 - 1 x 2Dark TurquoisePart 99781Element 6249418×1
Trans-Red
1 piece
Tile Round 1 x 1Trans-RedPart 98138Element 6514189 or 6258607×1
[No Color/Any Color]
1 piece
Sticker Sheet for Set 21371-1[No Color/Any Color]Part 10119087Element 6630722×1
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.