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.
Brick Curved 1 x 3 x 2WhitePart 33243Element 4141668 or 4128644×2
Brick Curved 1 x 4 x 1 1/3 No Studs, Lowered Inside SupportWhitePart 6191Element 4297949 or 619101×6
Brick Curved 3 x 1 No StudsWhitePart 50950Element 6548268 or 4249112×4
Brick Round 2 x 2 Dome Top, Blocked Open Stud, Bottom Axle HolderWhitePart 30367b×2
Brick Round 2 x 2 with Axle HoleWhitePart 3941Element 6601920 or 614351×4
Brick Sloped 30° 1 x 1 x 2/3 (Cheese Slope)WhitePart 54200Element 6550179 or 4504369×4
Plate 1 x 3WhitePart 3623Element 6552105 or 6550144×2
Plate 1 x 4WhitePart 3710Element 6552108 or 6548266×1
Plate 2 x 12WhitePart 2445Element 6552091 or 244501×1
Plate 2 x 16WhitePart 4282Element 6609534 or 4119227×2
Plate 4 x 8WhitePart 3035Element 6609533 or 303501×2
Technic Beam 1 x 5 ThickWhitePart 32316Element 4249021 or 4140465×9
Technic Brick 1 x 2 with Axle Hole Type 2 [X Opening]WhitePart 32064b×4
Technic Brick 1 x 6 [5 Pin Holes]WhitePart 3894Element 389401×4
Tile 1 x 8 with GrooveWhitePart 4162Element 6552110 or 416201×1
Wedge Plate 4 x 2 LeftWhitePart 41770Element 6552119 or 4161326×1
Wedge Plate 4 x 2 RightWhitePart 41769Element 6552118 or 4160857×1
Blue
41 pieces
Technic Axle Pin with Friction Ridges LengthwiseBluePart 43093Element 4309323 or 4206482×41
Trans-Red
6 pieces
Technic Tooth 1 x 3 with Axle Hole [Rounded Underside]Trans-RedPart 41669Element 4163567×6
Trans-Brown
4 pieces
Brick Curved 2 x 2 with Lip, No StudsTrans-BrownPart 30602Element 6507872 or 6171717×2
Technic Tooth 1 x 3 with Axle Hole [Rounded Underside]Trans-BrownPart 41669Element 6052989 or 4543608×2
Pearl Light Gray
3 pieces
Bucket with Handle Holes and 5 Bottom Holes - Center Bottom Stud HolderPearl Light GrayPart 48245Element 4297956 or 4216592×2
Technic Engine Tunable, Block with Trapezoidal Air ScoopPearl Light GrayPart 46453Element 4494989 or 4297957×1
Tan
3 pieces
Technic Axle Pin without Friction Ridges LengthwiseTanPart 3749Element 4666579 or 4186017×3
Light Gray
2 pieces
Technic Gear 8 ToothLight GrayPart 3647Element 3647021 spare in the box×2
Trans-Orange
2 pieces
Tile 1 x 2 with GrooveTrans-OrangePart 3069bElement 6514225 or 6251306×2
Trans-Neon Green
1 piece
Brick Round 2 x 2 with Axle HoleTrans-Neon GreenPart 3941Element 6273157 or 611649×1
[No Color/Any Color]
1 piece
Sticker Sheet for Set 8682-1[No Color/Any Color]Part 56628Element 4296377×1
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.