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.

Message Decoder

Checking

6831 Message Decoder

28 pieces in 18 part and color combinations, plus 1 minifigure.

The piece count includes the 6 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.

Show

Piece checklist

Black 19 pieces

  • Antenna 1 x 4 with Rounded Top Black Part 3957a ×2
  • Bar 1 x 6 [Open Studs] Black Part 4873 ×1
  • Brick Sloped 33° 3 x 2 with 'POLICE' Print (Space Police I) Black Part 3298pr0013 ×1
  • Hinge Brick 1 x 2 Top Plate Thin Black Part 3938 Element 393826 ×1
  • Lever Small Base with Black Lever Black Part 298c02 Element 73587 1 spare in the box ×2
  • Plate 2 x 10 Black Part 3832 Element 383226 ×1
  • Plate 2 x 2 Black Part 3022 Element 302226 ×1
  • Plate 2 x 4 Black Part 3020 Element 302026 ×1
  • Plate Special 1 x 4 Offset with Bar Holes Black Part 4590 Element 6002559 or 4278029 ×1
  • Plate Special 2 x 2 with Wheels Red Black Part 122c01 ×2
  • Wheel Arch, Mudguard 2 x 4 [Smooth] Black Part 3787 ×2
  • Wheel Balloon with Axle hole Black Part 4288 Element 4113076 or 428876 ×4

Blue 5 pieces

  • Brick Sloped 45° 2 x 2 Blue Part 3039 Element 303923 ×1
  • Brick Special 1 x 1 with Headlight Blue Part 4070 Element 407023 ×2
  • Hinge Brick 1 x 2 Base Blue Part 3937 Element 393723 ×1
  • Wedge Plate 3 x 4 without Stud Notches Blue Part 4859 ×1

Trans-Red 4 pieces

  • Dish 2 x 2 Inverted [Radar] Trans-Red Part 4740 Element 6580377 or 6245303 ×2
  • Plate Round 1 x 1 with Solid Stud Trans-Red Part 6141 Element 6514051 or 6208450 ×2

Minifigures 1 figure

  • Space Police I 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.