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.

Yamaha MT-10 SP

Checking

42159 Yamaha MT-10 SP

1,478 pieces in 242 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.

Every bag and the box. Shake out each bag, check its corners and seams, and look inside the empty box.
Inside what you have built. Small pieces lodge inside tubes, under plates and between studs. Turn the model over and look.
The last few steps. Compare each recent step with its parts callout. A piece used in the wrong place earlier leaves you one short later.
Look-alike colors. 12 parts in this set come in two colors that are easy to mix up; they are listed below.
The spare pieces. This set comes with 30 spare pieces, marked on each row of the checklist. One may be the piece you need.
The floor and your building area. Check under furniture, the chair and the edges of your building surface.

Look-alike colors in this set

These parts appear in this set in two colors that are easy to confuse. If you are one short in one color, check whether it went in where the other color belongs. Each color has its own element ID in the parts list at the back of the instructions.

Technic Panel Fairing #7 3L Very Small Smooth, Side A Black ×4 Trans-Brown ×1 Trans-Brown is see-through: hold the piece up to a light.
Technic Panel Fairing #8 3L Very Small Smooth, Side B Black ×4 Trans-Brown ×1 Trans-Brown is see-through: hold the piece up to a light.
Technic Axle and Pin Connector Angled #3 - 157.5° Black ×9 Dark Bluish Gray ×1 Black is darker than Dark Bluish Gray.
Technic Beam 1 x 13 Thick Black ×4 Dark Bluish Gray ×2 Black is darker than Dark Bluish Gray.
Technic Beam 1 x 7 Thick with Alternating Holes Black ×1 Dark Bluish Gray ×4 Black is darker than Dark Bluish Gray.
Technic Panel Curved 5 x 7 Parallelogram Left Black ×1 Dark Bluish Gray ×1 Black is darker than Dark Bluish Gray.

6 more look-alike pairs

Technic Panel Curved 5 x 7 Parallelogram Right Black ×1 Dark Bluish Gray ×1 Black is darker than Dark Bluish Gray.
Technic Panel Triangle 5 x 4 Left Black ×1 Dark Bluish Gray ×1 Black is darker than Dark Bluish Gray.
Technic Panel Triangle 5 x 4 Right Black ×1 Dark Bluish Gray ×1 Black is darker than Dark Bluish Gray.
Technic Pin Connector Hub with 1 Axle Black ×9 Dark Bluish Gray ×2 Black is darker than Dark Bluish Gray.
Technic Pin Connector Hub with 1 Pin with Friction Ridges Lengthwise [Centered Friction Ridge] Black ×15 Dark Bluish Gray ×2 Black is darker than Dark Bluish Gray.
Technic Pin Connector Round 1L [Beam] Black ×7 Dark Bluish Gray ×10 Black is darker than Dark Bluish Gray.

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.