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.
872 pieces in 203 part and color combinations, plus 4 minifigures.
LEGO counts 882 pieces. This inventory comes from a separate parts catalog and lists 887, including the 15 parts inside the minifigures; 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.
Technic Driving Ring Extension, 4 RidgesLight Bluish GrayPart 32187Element 4278756 or 4209329×2
Technic Gear 16 Tooth with Round Holes [Old Style]Light Bluish GrayPart 4019Element 4562487 or 4211563×1
Containers
2 pieces
Cupboard 2 x 3 x 2 with Solid StudsOrangePart 4532Element 6106114 or 4520812×1
Cupboard 2 x 3 x 2 DoorWhitePart 4533Element 4261470 or 4248214×1
Technic Beams Special
2 pieces
Technic Beam 3 x 0.5 Liftarm with Boss and Pin / CrankLight Bluish GrayPart 33299aElement 4211688×2
Technic Special
2 pieces
Technic Ball Joint with Through Axle HoleBlackPart 53585Element 4286267×2
Transportation - Land
2 pieces
Seat / Chair 2 x 2Reddish BrownPart 4079Element 4211206×2
Minifigures
4 figures
Astromech Droid, R2-D2, White Dome, 30361c BodyMinifigure, checked as a whole figure×1
Ahsoka Tano, Padawan, Light Bluish Gray LegsMinifigure, checked as a whole figure×1
RottaMinifigure, checked as a whole figure×1
Anakin Skywalker, Pilot Uniform (Clone Wars) (3626b Head)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.
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.