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.

Tri-Bike

Checking

3531 Tri-Bike

29 pieces in 13 part and color combinations.

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

Znap 23 pieces

  • Znap Beam 1/2 Circle Radius 2L Black Part 32205 Element 4128656 or 4120409 ×2
  • Znap Beam 16, 9 Holes, 5 Bends Black Part 32208 Element 4120423 ×1
  • Znap Grid 9 x 7, 15 Holes Black Part 32213 Element 4125298 or 4125163 ×1
  • Znap Connector 3 x 3 - 4 way A (Axial) Dark Gray Part 32221 Element 4120479 ×2
  • Znap Beam 16, 9 Holes, 5 Bends Green Part 32208 Element 4120484 ×1
  • Znap Beam 3, 1 Hole Green Part 32210 Element 4128661 or 4120412 ×2
  • Znap Beam 9, 8 Holes, Triangular Green Part 32214 Element 4125310 or 4125161 ×2
  • Znap Beam Double Curve 4 Holes Green Part 32218 Element 4125306 or 4120487 ×1
  • Znap Connector 1 x 3 - 2 way A Light Gray Part 32212 Element 4120191 ×3
  • Znap Connector 3 x 3 - 4 way B (Beam) Purple Part 32211 Element 4120200 ×8

Technic Axles 3 pieces

  • Technic Axle 12 White Part 3708 Element 4655283 or 4222794 ×1
  • Technic Axle 5.5 with Stop [Flat Short End] White Part 32209 Element 4120471 ×2

Wheels and Tyres 3 pieces

  • Wheel 68mm Znap Propeller (9 x 2) Black Part 32220 Element 4120446 ×3

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.