What to Do If a Building Set Has Missing or Broken Pieces

You are two-thirds through a build, step 84 wants a specific small connector, and it is not there. The bag is empty, the tray is empty, and the model is stuck.

It is a genuinely deflating moment, and it happens to everyone eventually. The useful thing to know is that in most cases the piece is not actually missing — and in the cases where it is, it is a much smaller problem than it feels like.

First: where pieces actually hide

Work through these in order before concluding anything. This resolves the large majority of cases.

1. Inside the bag it came from. Small flat pieces stick to the inside of a poly bag through static and stay there when you tip it out. Turn the bag inside out rather than shaking it.
2. Under the instruction booklet. The single most common hiding place. Lift the booklet rather than sliding it.
3. Already on the model. Very common with connectors, where you used the right shape at the wrong step. Compare the last few pages against what you have actually built.
4. In the box corners. Cardboard boxes have folded flaps, and small pieces get into them during shipping. Use a torch.
5. On the floor. Especially against a skirting board or under furniture. Dark pieces on a dark floor are effectively invisible — which is why building on a light bedsheet saves so much time.
6. In the spares bag. If you sorted spares aside at the start, check there. What looks like a missing piece is sometimes a piece you filed away as extra.

Second: is it actually the right piece?

Before reporting a shortage, rule out two things that look identical to one.

A near-identical part. Many sets contain pieces that differ by one stud or a fraction of a millimetre in height. If you have a spare of a similar shape and are short of another, you almost certainly swapped them at an earlier step.

A miscounted step. Instruction booklets show quantities per step in small type near the piece diagram. Check whether the step wanted two of something and you read it as one, twenty steps ago.

A quick diagnostic: if you are short of exactly one piece and have exactly one unexpected spare, it is a swap, not a shortage. If you are short and have no spare, it is more likely genuine.

This happens far more on big multi-model kits than on small ones, simply because there are more near-identical parts in the box. On something like a 6-in-1 fire truck set, where the same pieces serve six different vehicles, a swapped connector at step 20 is the usual explanation for a shortage at step 80.

Third: reporting it properly

If it is genuinely missing, how you report it decides how fast it is resolved. A message saying "a piece is missing" cannot be actioned. Send this instead:

• The set name and your order number.
• The step number from the booklet where the piece is needed.
• A photo of that page, with the piece circled.
• The quantity you are short by.
• A photo of your build so far, which lets the seller confirm nothing was mis-assembled.

That set of five things usually turns a week of back-and-forth into a single reply. Keep the packaging until the build is finished, because batch information printed on the bag sometimes matters.

Broken pieces are a different problem

Missing and broken are handled differently, and it is worth knowing which you have.

The distinction that matters to a seller is defect versus damage. A brick that cracked the first time it was clipped is a moulding fault. One that snapped after being levered apart with a screwdriver is not, and no warranty covers that. Being straightforward about which happened tends to get a better outcome than being vague.

The special case: lights and moving parts

Sets with wiring or motion have one failure mode that looks like a broken piece but is not. On a lit or moving model — a rotating LED aquarium scene, for instance — a dead light is almost always a wire pulled loose at the joint, not a failed LED. Check the connection at the board before reporting a fault.

What a structural warranty actually means

Not all guarantees mean the same thing, so it is worth reading before you need it. A structural warranty — like the five-year one that comes with sets such as our 1878-piece Titanic model or the poseable mechanical eagle — covers the integrity of the pieces themselves: bricks that crack, warp, or fail to grip because of a fault in the moulding.

What it typically does not cover is loss. A piece that went under the sofa is not a manufacturing defect. Most sellers, ours included, will still help with a replacement part in that situation, but treat it as goodwill rather than an entitlement — and it is a strong argument for buying from a seller you can actually reach.

If the piece cannot be replaced

Occasionally a part is genuinely unavailable. You still have options, roughly in order of how well they work:

• Substitute from the spares. Most sets ship a handful of extras. A structurally equivalent piece in the wrong colour is almost always better than an unfinished model.
• Substitute from another set. If the bricks are compatible with major brands, your existing collection is a parts bin.
• Rebuild the section differently. On a large model, one connector can often be replaced by two smaller pieces achieving the same join.
• Leave it, if it is cosmetic. A missing decorative tile on the back of a display model is not worth stalling the build over.

How to make this less likely next time

1. Open one numbered bag at a time. The best protection there is against loss.
2. Build on a light bedsheet. Dropped pieces stay visible and in reach.
3. Bag the spares immediately, and label them.
4. Do not force a piece. If it needs real pressure, it is the wrong piece — forcing it is how cracks start.
5. Keep the booklet with the pieces between sessions, in the same bag.

Our guide on sorting and storing building blocks goes through the storage side properly, and it is the single best defence against this whole category of problem.

Common questions

How many spare pieces should a set include?

Usually a handful of small, easily lost parts — connectors, small tiles, occasionally a wheel. Do not expect spares of large structural pieces. If you find extras at the end of a build and the model looks correct, those are spares, not a mistake.

Can I glue a cracked brick?

You can, and it works for a display model that will never be dismantled. Do not glue anything in a set that gets rebuilt — you convert a repairable set into a permanently reduced one. Replacement is better where it is available.

How long should a replacement part take?

Ask when you report it. What matters more than the number is getting a specific answer rather than a vague one, and that comes from sending the step number and photos up front.

Does a warranty cover a set my child pulled apart with pliers?

No. Structural warranties cover defects in the pieces, not damage from force. Say plainly what happened — most sellers will still sell you the part, and honesty gets a faster reply than a disputed claim.

Where to start

The best insurance against all of this is buying from somewhere that will actually answer. Every set in our bestselling building block sets carries a structural warranty and a contactable seller behind it, which is worth more on the day something goes wrong than any feature on the box.

Choosing your next set? See how to choose a building block set, and if it is a lit model, how LED light kits work covers the wiring failures worth knowing about before you build.