Free tool

LEGO Missing Piece Checker

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.

Celebrating 40 Years of Hands-on Learning

Checking

4002020 Celebrating 40 Years of Hands-on Learning

915 pieces in 340 part and color combinations, plus 1 minifigure.

The official piece count includes the 4 parts inside the set's minifigures, which this inventory lists separately. Spare parts are counted in neither figure.

Before you call it missing

Builders who report a missing piece often find it in one of these places. Tick each one off as you look.

Every bag and the box. Shake out each bag, check its corners and seams, and look inside the empty box.
Inside what you have built. Small pieces lodge inside tubes, under plates and between studs. Turn the model over and look.
The last few steps. Compare each recent step with its parts callout. A piece used in the wrong place earlier leaves you one short later.
Look-alike colors. 8 parts in this set come in two colors that are easy to mix up; they are listed below.
The spare pieces. This set comes with 56 spare pieces, marked on each row of the checklist. One may be the piece you need.
The floor and your building area. Check under furniture, the chair and the edges of your building surface.

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 Round 1 x 1 Open Stud Red ×2 Trans-Red ×1 Trans-Red is see-through: hold the piece up to a light.
Plate 1 x 2 White ×2 Trans-Clear ×1 Trans-Clear is see-through: hold the piece up to a light.
Tile 1 x 2 with Groove Dark Turquoise ×1 Medium Azure ×2 Dark Turquoise is darker than Medium Azure.
Plate 1 x 1 Tan ×1 Dark Tan ×6 Tan is lighter than Dark Tan.
Plate 1 x 3 Tan ×1 Dark Tan ×13 Tan is lighter than Dark Tan.
Plate 2 x 2 Tan ×1 Dark Tan ×2 Tan is lighter than Dark Tan.

3 more look-alike pairs

Plate 2 x 3 Tan ×2 Dark Tan ×6 Tan is lighter than Dark Tan.
Plate 1 x 1 Black ×1 Trans-Brown ×2 Trans-Brown is see-through: hold the piece up to a light.
Plate Special 1 x 2 Rounded with 2 Open Studs Black ×3 Dark Bluish Gray ×2 Black is darker than Dark Bluish Gray.

Piece checklist

Technic Beams 19 pieces

Technic Beam 1 x 3 Thick Black Part 32523 Element 4142822 or 3252326 ×2
Technic Beam 1 x 9 Thick Light Bluish Gray Part 40490 Element 6102449 or 4211866 ×10
Technic Beam 1 x 7 Thin Red Part 32065 Element 6613783 or 6349634 ×4
Technic Beam 1 x 3 Thick Yellow Part 32523 Element 4153707 ×3

Technic Special 18 pieces

Gearbox 4 x 4 x 1 2/3 with 1 x 2 Cutouts, Pin Holes Black Part 6585 Element 6169982 or 4500902 ×1
Technic Cam Black Part 6575 Element 4143187 ×2
Technic Link Tread Wide with Two Pin Holes, Reinforced Dark Bluish Gray Part 88323 Element 4566742 ×15

Technic Gears 15 pieces

Technic Gear 12 Tooth Double Bevel Black Part 32270 Element 4177431 ×3
Technic Gear 36 Tooth Double Bevel Black Part 32498 Element 4255563 or 4177434 ×1
Technic Tread Sprocket Wheel Small 6 Tooth Black Part 57520 Element 4662228 or 4544527 ×2
Technic Gear 24 Tooth [New Style with Single Axle Hole] Dark Bluish Gray Part 3648b Element 6133119 or 4514558 ×5
Technic Gear 12 Tooth Bevel Tan Part 6589 Element 4565452 or 4514556 ×2
Technic Gear 20 Tooth Double Bevel with Axle Hole Type 1 [+ Opening] Tan Part 18575 Element 6346517 or 6084724 ×2

Bricks Curved 11 pieces

Brick Curved 2 x 1 No Studs [1/2 Bow] Black Part 11477 Element 6047276 ×1
Brick Arch 1 x 3 Bright Pink Part 4490 Element 6054930 ×1
Brick Arch 1 x 6 Raised Arch Dark Bluish Gray Part 92950 Element 4620760 ×1
Brick Arch 1 x 4 Reddish Brown Part 3659 Element 6177697 or 6088713 ×2
Brick Curved 2 x 1 No Studs [1/2 Bow] Reddish Brown Part 11477 Element 6069984 ×2
Brick Curved 2 x 1 No Studs [1/2 Bow] White Part 11477 Element 6552145 or 6548276 ×2
Brick Curved 4 x 1 Double, No Studs White Part 93273 Element 6552143 or 6023806 ×2

Plates Wedged 11 pieces

Wedge Plate 2 x 2 Cut Corner Dark Tan Part 26601 Element 6228921 ×1
Wedge Plate 3 x 2 Left Dark Tan Part 43723 Element 6002843 ×2
Wedge Plate 3 x 2 Right Dark Tan Part 43722 Element 6002847 ×2
Wedge Plate 6 x 3 Left Dark Tan Part 54384 Element 6002851 ×1
Wedge Plate 6 x 3 Right Dark Tan Part 54383 Element 6002849 ×1
Wedge Plate 6 x 3 Left Light Bluish Gray Part 54384 Element 4282789 ×2
Wedge Plate 6 x 3 Right Light Bluish Gray Part 54383 Element 4282786 ×2

Technic Bushes 9 pieces

Technic Bush Light Bluish Gray Part 3713 Element 6275844 or 6271817 1 spare in the box ×1
Technic Bush 1/2 Smooth with Axle Hole Semi-Reduced Light Bluish Gray Part 32123b Element 6271165 or 4211573 1 spare in the box ×4
Technic Bush 1/2 Smooth with Axle Hole Semi-Reduced Yellow Part 32123b Element 6271167 or 3212324 1 spare in the box ×4

Tiles Special 9 pieces

Tile Special Round 2 x 2 with Hole Dark Tan Part 15535 Element 6132790 ×1
Tile Special Round 2 x 2 with Hole Light Bluish Gray Part 15535 Element 6179186 ×2
Tile, Star with Stud Holder, Pin Hole Pearl Gold Part 11609 Element 6651230 or 6184647 1 spare in the box ×3
Tile Special 1 x 2 with Sloped Walls AKA Money / Gold Bar [Ingot] Reddish Brown Part 99563 Element 6261744 ×2
Tile Special Round 1 x 1 with Hollow Bar White Part 20482 Element 6186681 or 6178492 1 spare in the box ×1

Windows and Doors 8 pieces

Window 1 x 2 x 2 Flat Front Black Part 60592 Element 6382697 or 4521439 ×1
Window 1 x 2 x 2 Flat Front Tan Part 60592 Element 6387150 or 6378142 ×3
Window 1 x 4 x 3 without Shutter Tabs Tan Part 60594 Element 4578109 ×4

Minifig Accessories 6 pieces

Equipment Paint Roller Brush Handle Smooth Handle Light Bluish Gray Part 34076 Element 6253856 ×1
Sports Roller Skate Light Bluish Gray Part 11253 Element 6217791 1 spare in the box ×1
Equipment Frying Pan Pearl Gold Part 4528 Element 6138068 ×1
Equipment Telescope / Torch / Spyglass, Support Round 1 x 1 x 1 2/3 Pearl Gold Part 64644 Element 4538126 ×2
Equipment Candlestick White Part 37762 Element 6234807 ×1

Panels 5 pieces

Panel 1 x 2 x 1 [Rounded Corners] Tan Part 4865b Element 6146221 ×1
Panel 1 x 4 x 2 with Side Supports - Hollow Studs Tan Part 14718 Element 6195544 ×3
Panel 1 x 6 x 5 with Gold '40 YEARS LEGO EDUCATION' Print White Part 59349pr0003 Element 6345026 ×1

Wheels and Tyres 5 pieces

Tyre 14 x 4 Smooth Small Single [New Style] Black Part 59895 Element 4516843 or 4507700 1 spare in the box ×2
Technic Wedge Belt Wheel [aka Pulley] Pearl Gold Part 4185 Element 6323675 or 6257902 ×3

Animals / Creatures 4 pieces

Animal, Rodent, Rat / Mouse with Black Eyes Print Dark Tan Part 36756pr0001 Element 6226594 or 6226382 ×1
Animal, Frog Green Part 33320 Element 6171101 or 4157270 ×3

Bars, Ladders and Fences 4 pieces

Bar 2L with Towball Dark Bluish Gray Part 22484 Element 6364352 or 6360117 ×1
Bar 1L with Clip [Cut Edges and One Side Hole] [Gap in Clip] Orange Part 48729b Element 6278159 or 6223596 1 spare in the box ×1
Fence Lattice 1 x 4 x 1 Pearl Gold Part 3633 Element 4536675 ×1
Bar 1 x 3 (Radio Handle, Phone Handset) Red Part 6190 Element 4558598 or 4108047 ×1

Technic Steering, Suspension and Engine 4 pieces

Technic Link 1 x 6 without Stoppers Black Part 32005a Element 4629921 or 4530733 ×1
Technic Engine Connecting Rod Light Bluish Gray Part 2852 Element 6000018 or 4655728 ×2
Technic Universal Joint 3L [Complete Assembly] Light Bluish Gray Part 61903 Element 6335279 or 6321309 ×1

Minifig Lower Body 2 pieces

Leg Skeleton Black Part 6266 Element 6240496 or 6038453 ×2

Plants & Trees 2 pieces

Plant, Flower, Minifig Accessory with 7 Thick Petals and Pin Dark Pink Part 32606 Element 6206151 1 spare in the box ×1
Plant, Flower, Plate Round 1 x 1 with 5 Petals Light Bluish Gray Part 24866 Element 6343322 1 spare in the box ×1

Bricks Wedged 1 piece

Brick Wedged, Curved 1 x 2 x 2/3 No Studs, Wing End Light Bluish Gray Part 47458 Element 6375710 or 6254402 ×1

Energy Effects 1 piece

Wave / Flame Small with Pin Trans-Orange Part 37775 Element 6514274 or 6357747 1 spare in the box ×1

String, Bands and Reels 1 piece

Technic Rubber Belt Medium [26mm ID] [Round Cross Section] Blue Part 85545 Element 6049730 or 4544147 ×1

Technic Beams Special 1 piece

Technic Beam 3 x 0.5 Liftarm with Boss and Blocked, Squared Pin Hole Black Part 61408 Element 6313520 ×1

Tools 1 piece

Brick and Axle Separator v2.0 Dark Turquoise Part 96874 Element 6254100 ×1

Transportation - Land 1 piece

Wheel Arch, Mudguard 2 x 4 Studded with Hole Black Part 60212 Element 4600178 or 4518608 ×1

Minifigures 1 figure

Elf - Bright Green Torso, Red Legs, Bright Green Hat Minifigure, checked as a whole figure ×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.

Request a replacement from LEGO

Buy the piece

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.