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.
Duplo Train Wagon Base 4 x 8 with Light Bluish Gray Wheels and Moveable HookDark Bluish GrayPart 31300c03Element 4515413 or 4265467×1
Duplo Brick 1 x 2 x 2 with Wood Grain & 'FRAGILE' PrintDark OrangePart 4066pr0172Element 4271062 or 4216308×1
Duplo Brick 2 x 2Dark OrangePart 3437Element 4583791 or 4158534×1
Duplo Brick 2 x 2Dark RedPart 3437Element 4541375 or 4196417×2
Duplo Brick 2 x 4Dark RedPart 3011Element 4541374 or 4196413×1
Duplo Brick 2 x 4 x 2 with 2 x 2 Square ArchDark RedPart 6394Element 4265002×2
Duplo Container Box 4 x 4 with Studs on Corners with Thomas & Friends Truck Face PrintLight Bluish GrayPart 47423pr0002Element 4262121×1
Duplo Container Box, 4 x 4 with Studs on Corners, with Thomas & Friends Truck PrintLight Bluish GrayPart 47423pr0003Element 4262123×1
Duplo Brick 1 x 2 x 2 with Traffic Signal Single PrintRedPart 4066pr0213Element 4265326×1
Duplo Brick 2 x 2RedPart 3437Element 4583321 or 343721×4
Duplo Brick 2 x 2 with Red, Dark Red, and Tan Bricks PrintRedPart 3437pr9992Element 4265296×3
Duplo Brick 2 x 4 x 2 Curved Top with 'TIDMOUTH' and Clock PrintRedPart 31213pr0006Element 4265302×1
Duplo Brick 2 x 4 x 2 with 2 x 2 Square ArchRedPart 6394Element 639421×4
Duplo Loading Chute / Silo Sliding Door Panel / LidRedPart 31026Element 4494677 or 3102621×1
Duplo Brick 2 x 2TanPart 3437Element 4583322 or 4166963×1
Duplo Plate 2 x 8TanPart 44524Element 4183797×1
Duplo Plate 4 x 8TanPart 4672Element 6288592 or 6184966×1
Duplo Turntable 2 x 2 with Square TopVery Light Bluish GrayPart 44538Element 4242419×1
Duplo Brick 2 x 4WhitePart 3011Element 301101×1
Duplo Fence 1 x 6 x 2 Paled (Picket)WhitePart 6497Element 4100729 or 649701×1
Duplo Plate 2 x 4YellowPart 40666Element 4160152×2
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.