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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.

Basic Building Set

Checking

740 Basic Building Set

530 pieces in 143 part and color combinations.

LEGO counts 525 pieces. This inventory comes from a separate parts catalog and lists 530; the two do not always count the same elements, so their totals differ. 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.

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.

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Piece checklist

Bricks 143 pieces

  • Brick 1 x 1 Red Part 3005 Element 300521 ×8
  • Brick 1 x 2 Red Part 3004 Element 4613961 or 300421 ×8
  • Brick 1 x 3 Red Part 3622 Element 362221 ×6
  • Brick 1 x 4 Red Part 3010 Element 301021 ×6
  • Brick 1 x 6 Red Part 3009 Element 300921 ×10
  • Brick 1 x 8 Red Part 3008 Element 300821 ×4
  • Brick 2 x 2 Red Part 3003 Element 4103590 or 300371 ×8
  • Brick 2 x 3 Red Part 3002 Element 300271 or 300221 ×4
  • Brick 2 x 4 Red Part 3001 Element 300121 ×5
  • Brick 1 x 1 Trans-Clear Part 3005 Element 6514207 or 6220959 ×6
  • Brick 1 x 1 Yellow Part 3005 Element 300524 ×16
  • Brick 1 x 2 Yellow Part 3004 Element 4613966 or 300424 ×16
  • Brick 1 x 3 Yellow Part 3622 Element 362224 ×12
  • Brick 1 x 4 Yellow Part 3010 Element 301024 ×10
  • Brick 1 x 6 Yellow Part 3009 Element 300924 ×12
  • Brick 1 x 8 Yellow Part 3008 Element 300824 ×4
  • Brick 2 x 2 Yellow Part 3003 Element 4103588 or 300374 ×5
  • Brick 2 x 4 Yellow Part 3001 Element 300124 ×1
  • Brick 2 x 8 Yellow Part 3007 Element 4639693 or 300724 ×2

Bricks Sloped 124 pieces

  • Brick Sloped 45° 2 x 1 Double / Inverted with Hollow Bottom Red Part 3049c ×1
  • Brick Sloped 45° 2 x 1 Double with Ovoid Bottom Pin Red Part 3044b Element 304421 ×1
  • Brick Sloped 45° 2 x 1 with Bottom Pin Red Part 3040b Element 4121934 or 304021 ×6
  • Brick Sloped 45° 2 x 2 Red Part 3039 Element 303921 ×12
  • Brick Sloped 45° 2 x 2 Double Red Part 3043 Element 304321 ×2
  • Brick Sloped 45° 2 x 2 Double Concave Red Part 3046a Element 4218892 or 4200489 ×12
  • Brick Sloped 45° 2 x 3 Red Part 3038 Element 6303213 or 4195081 ×8
  • Brick Sloped 45° 2 x 4 Red Part 3037 Element 303721 ×8
  • Brick Sloped 45° 2 x 4 Double Red Part 3041 Element 4144003 or 304121 ×1
  • Brick Sloped 45° 2 x 8 Red Part 4445 Element 4550322 or 4239184 ×6
  • Brick Sloped Inverted 33° 3 x 2, No Connections between Studs, Ovoid Bottom Pin Red Part 3747a Element 374721 ×5
  • Brick Sloped Inverted 34° 3 x 1 without Internal Stopper Red Part 4287a ×4
  • Brick Sloped Inverted 45° 2 x 1 Red Part 3665 Element 366521 ×18
  • Brick Sloped Inverted 45° 2 x 2 [Ovoid Bottom Pin, Bar-sized Stud Holes] Red Part 3660 Element 366021 ×4
  • Brick Sloped 33° 3 x 1 Yellow Part 4286 Element 428624 ×4
  • Brick Sloped 33° 3 x 2 Yellow Part 3298 Element 329824 ×3
  • Brick Sloped 45° 2 x 1 with Bottom Pin Yellow Part 3040b Element 4121965 or 304024 ×8
  • Brick Sloped 45° 2 x 2 Yellow Part 3039 Element 303924 ×2
  • Brick Sloped 45° 2 x 2 Double Convex Yellow Part 3045 Element 6378402 or 4271076 ×2
  • Brick Sloped 45° 2 x 4 Yellow Part 3037 Element 4219911 or 303724 ×4
  • Brick Sloped Inverted 33° 3 x 2, No Connections between Studs, Ovoid Bottom Pin Yellow Part 3747a ×3
  • Brick Sloped Inverted 34° 3 x 1 without Internal Stopper Yellow Part 4287a ×2
  • Brick Sloped Inverted 45° 2 x 1 Yellow Part 3665 Element 366524 ×6
  • Brick Sloped Inverted 45° 2 x 2 [Ovoid Bottom Pin, Bar-sized Stud Holes] Yellow Part 3660 Element 366024 ×2

Plates 96 pieces

  • Plate 1 x 2 Black Part 3023 Element 302326 ×2
  • Plate 1 x 3 Black Part 3623 Element 362326 ×2
  • Plate 1 x 4 Black Part 3710 Element 371026 ×4
  • Plate 1 x 8 Black Part 3460 Element 346026 ×8
  • Plate 2 x 2 Black Part 3022 Element 302226 ×2
  • Plate 2 x 4 Black Part 3020 Element 302026 ×4
  • Plate 2 x 6 Black Part 3795 Element 379526 ×2
  • Plate 2 x 8 Black Part 3034 Element 303426 ×1
  • Plate 1 x 1 Red Part 3024 Element 302421 Also in Trans-Red ×4
  • Plate 1 x 2 Red Part 3023 Element 302321 ×8
  • Plate 1 x 3 Red Part 3623 Element 362321 ×2
  • Plate 1 x 4 Red Part 3710 Element 371021 ×4
  • Plate 1 x 6 Red Part 3666 Element 366621 ×2
  • Plate 1 x 8 Red Part 3460 Element 346021 ×2
  • Plate 2 x 2 Red Part 3022 Element 4613974 or 302221 ×2
  • Plate 2 x 3 Red Part 3021 Element 302121 ×2
  • Plate 2 x 4 Red Part 3020 Element 302021 ×4
  • Plate 2 x 6 Red Part 3795 Element 379521 ×2
  • Plate 2 x 8 Red Part 3034 Element 303421 ×2
  • Plate 4 x 6 Red Part 3032 Element 303221 ×1
  • Plate 4 x 8 Red Part 3035 Element 303521 ×2
  • Plate 6 x 8 Red Part 3036 Element 303671 or 303621 ×2
  • Plate 1 x 1 Trans-Green Part 3024 Element 6513967 or 6252046 ×1
  • Plate 1 x 1 Trans-Red Part 3024 Element 6513963 or 6252042 Also in Red ×2
  • Plate 1 x 1 Yellow Part 3024 Element 302424 ×2
  • Plate 1 x 2 Yellow Part 3023 Element 302324 ×4
  • Plate 1 x 3 Yellow Part 3623 Element 362324 ×2
  • Plate 1 x 4 Yellow Part 3710 Element 371024 ×4
  • Plate 1 x 6 Yellow Part 3666 Element 366624 ×2
  • Plate 1 x 8 Yellow Part 3460 Element 346024 ×2
  • Plate 2 x 2 Yellow Part 3022 Element 4613978 or 302224 ×2
  • Plate 2 x 3 Yellow Part 3021 Element 302124 ×2
  • Plate 2 x 4 Yellow Part 3020 Element 302024 ×2
  • Plate 2 x 6 Yellow Part 3795 Element 379524 ×1
  • Plate 2 x 8 Yellow Part 3034 Element 303424 ×2
  • Plate 4 x 6 Yellow Part 3032 Element 303224 ×1
  • Plate 4 x 8 Yellow Part 3035 Element 303524 ×2
  • Plate 6 x 8 Yellow Part 3036 Element 4552333 or 4166761 ×1

Windows and Doors 28 pieces

  • Door 1 x 4 x 5 with 4 Panes, Squared Base Red Part 3861b Element 386121 ×1
  • Door Sliding - Type 1 Red Part 4511 ×2
  • Window 1 x 2 x 3 Shutter Red Part 3856 Element 4189092 or 385621 ×4
  • Window 1 x 4 x 3 Red Part 3853 Element 385321 ×3
  • Glass for Window 1 x 4 x 3 Trans-Clear Part 3855 Element 4556520 or 4203330 ×2
  • Glass for Window 4 x 4 x 3 Roof Trans-Clear Part 4448 Element 4522040 or 4161146 ×2
  • Window 1 x 2 x 3 Pane White Part 3854 Element 385401 ×6
  • Door 1 x 4 x 5 Train Left with Red Bottom Half Print Yellow Part 4181pr0002 ×1
  • Door 1 x 4 x 5 Train Right with Red Bottom Half Print Yellow Part 4182pr0002 ×1
  • Window 1 x 2 x 3 Train Yellow Part 4035 Element 403524 ×2
  • Window 1 x 4 x 3 Train with All Studs Hollow Yellow Part 4033 Element 4264949 or 4111855 ×2
  • Window 4 x 4 x 3 Roof Yellow Part 4447 ×2

Hinges, Arms and Turntables 25 pieces

  • Hinge Plate 1 x 2 with 2 Fingers and Solid Studs Black Part 4276a ×2
  • Hinge Plate 1 x 2 with 3 Fingers [Solid Studs] Black Part 4275a ×6
  • Hinge Plate 2 x 4 with Articulated Joint - Female Black Part 3640 Element 364026 ×1
  • Hinge Plate 2 x 4 with Articulated Joint - Male Black Part 3639 Element 363926 ×1
  • Hinge Plate 2 x 5 with Large Hole [Complete Assembly] Black Part 3149bc01 Element 4161112 or 4106943 ×1
  • Hinge Tile 1 x 2 1/2 with 2 Fingers on Top Black Part 4531 Element 453126 ×4
  • Turntable 4 x 4 Square Base Black Part 3403 Element 340326 ×1
  • Turntable 4 x 4 Top Black Part 3404 Element 4221659 or 340426 ×1
  • Hinge Brick 1 x 4 [Lower] Red Part 3831 Element 6512257 or 6397573 ×2
  • Hinge Brick 1 x 4 [Upper] Red Part 3830 Element 6397607 or 6011464 ×2
  • Hinge Plate 1 x 2 with 2 Fingers and Solid Studs Yellow Part 4276a ×2
  • Hinge Plate 1 x 2 with 3 Fingers [Solid Studs] Yellow Part 4275a ×2

Wheels and Tyres 24 pieces

  • Tyre 43 x 17 Black Part 3634 Element 4523564 or 363426 ×4
  • Tyre Offset Tread 24 x 8 Black Part 3483 Element 4501048 or 348326 ×8
  • Wheel with Split Axle hole Light Gray Part 3482 Element 348202 ×12

Plates Special 18 pieces

  • Bracket 2 x 2 - 2 x 2 Black Part 3956 Element 6254808 or 6019217 ×2
  • Plate Special 1 x 2 with Ladder Black Part 4175 Element 6285241 or 6179557 ×2
  • Plate Special 1 x 8 with Door Rail Black Part 4510 Element 4286009 or 451026 ×4
  • Plate Special 2 x 2 with Towball Black Part 3729 Element 4124111 or 4107856 ×1
  • Plate Special 2 x 2 with Towball Socket, Short, 4 Slots Black Part 3730 Element 373026 ×1
  • Plate Special 3 x 2 with Rounded End, Hole Black Part 3176 Element 317676 or 317626 ×4
  • Plate Special 1 x 2 with 1 Stud without Groove (Jumper) Yellow Part 3794a ×4

Bricks Round and Cones 10 pieces

  • Brick Round 1 x 1 Open Stud Black Part 3062b Element 306226 ×6
  • Brick Round 2 x 2 with Axle Hole Black Part 3941 Element 614376 or 614326 ×4

Technic Bricks 10 pieces

  • Technic Brick 1 x 12 [11 Pin Holes] Red Part 3895 Element 389521 ×2
  • Technic Brick 1 x 16 [15 Pin Holes] Red Part 3703 Element 370321 ×2
  • Technic Brick 1 x 2 [1 Pin Hole] Red Part 3700 Element 370021 ×4
  • Technic Brick 1 x 8 [7 Pin Holes] Red Part 3702 Element 370221 ×2

Technic Pins 10 pieces

  • Technic Pin with Friction Ridges Lengthwise, without Center Slots Black Part 4459 ×4
  • Technic Axle Pin without Friction Ridges Lengthwise Light Gray Part 3749 Element 4184168 or 4154179 ×4
  • Technic Pin without Friction Ridges Lengthwise Light Gray Part 3673 Element 4184166 or 367302 ×2

Bricks Special 8 pieces

  • Brick Special 1 x 1 with Headlight Red Part 4070 Element 407021 ×6
  • Brick Special 1 x 1 with Headlight Yellow Part 4070 Element 407024 ×2

Plates Round Curved and Dishes 8 pieces

  • Plate Round 2 x 2 with Axle Hole Type 1 (+ Opening) Black Part 4032a Element 403226 ×2
  • Plate Round 1 x 1 with Solid Stud Trans-Yellow Part 6141 Element 6514056 or 6240216 ×6

Technic Axles 6 pieces

  • Technic Axle 10 Black Part 3737 Element 373726 ×2
  • Technic Axle 6 Black Part 3706 Element 370626 ×2
  • Technic Axle 8 Black Part 3707 Element 370726 ×2

Electronics 5 pieces

  • Motor, Train, 4.5V 12 x 4 x 3 1/3 Type III, Open Contacts Black Part upn0259c02 ×1
  • Battery Box, 4.5V, 4 x 24, 3 x C-Cell with Switch [Complete Assembly] Light Gray Part 4350c02 ×1
  • Electric Connector, 2 Way Male Squared Narrow Long [Complete Assembly] Light Gray Part 766c01 ×2
  • Wire 12V / 4.5V with Two Leads [Undetermined Length] Light Gray Part 74503 ×1

Bars, Ladders and Fences 4 pieces

  • Fence Lattice 1 x 4 x 1 Black Part 3633 Element 4187209 or 363326 ×4

Technic Bushes 4 pieces

  • Technic Bush Light Gray Part 3713 Element 4125313 or 659002 ×4

String, Bands and Reels 2 pieces

  • String Cord Medium Thickness 50cm Black Part 7916c50 ×1
  • String Reel Winch 2 x 4 x 2 (Light Gray Drum) Yellow Part 73037 Element 4109856 ×1

Transportation - Land 2 pieces

  • Tipper End Sloped Red Part 3436 ×2

Baseplates 1 piece

  • Baseplate 16 x 32 Light Gray Part 3857 Element 4219612 or 274802 ×1

Supports, Girders and Cranes 1 piece

  • Hook, Plate 1 x 2 with Crane Hook Left Red Part 3127 Element 4120019 ×1

Windscreens and Fuselage 1 piece

  • Windscreen 2 x 6 x 2, Wide Top Trans-Clear Part 4176 Element 4502193 or 4179426 ×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.

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