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.
LEGO counts 657 pieces. This inventory comes from a separate parts catalog and lists 658; 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.
Hose Rigid 3mm D. 3L / 2.4cmDark GrayPart 75c03Element 41186041 spare in the box×2
Technic Axle 3 with StudDark GrayPart 6587Element 4113884 or 658727×3
Technic Pin 3/4Dark GrayPart 32002Element 41098541 spare in the box×16
Dark Turquoise
8 pieces
Technic Pin Long with Friction Ridges Lengthwise and Stop Bush [3 Lateral Holes, Big Pin Hole]Dark TurquoisePart 32054Element 4140804 or 4120240×8
Metallic Silver
2 pieces
Technic Panel Dome 6 x 6 x 5 2/3 with R2-D2 Eye PrintMetallic SilverPart 51pr0002Element 4128502×1
Technic Panel Dome 6 x 6 x 5 2/3 with R2-D2 No Eye PrintMetallic SilverPart 51pr0001Element 4128501×1
Trans-Red
2 pieces
Plate Round 1 x 1 with Solid StudTrans-RedPart 6141Element 6514051 or 62084501 spare in the box×2
[No Color/Any Color]
1 piece
CD-Rom, for 9748[No Color/Any Color]Part 4128535×1
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.