The short answer
Decide early whether you are selling sealed sets, built or complete sets, minifigures or mixed bulk bricks. Find set numbers, check completeness against the instructions, set aside the minifigures, and remove clone bricks. Then check recent sold prices for the exact set number and condition, and list each type where its buyers look.
Choose your LEGO selling format
| What you have | What to record | What to compare |
|---|---|---|
| A sealed set | Set number, seals and box damage | Sales of the same sealed set |
| A used set | Missing pieces, figures, instructions and box | The same set with comparable contents |
| Minifigures | Front, back, accessories and cracks | The exact figure and its condition |
| Mixed bricks | Weight, brands, damage and what you removed | Similar mixed lots, with figures included or excluded |
Check set numbers against official instructions
A number moulded into a loose piece may identify its design, not the whole set. LEGO explains the difference between set, element and design numbers. Use a set number from the box or instruction booklet to search LEGO's official building-instruction archive.
If you have not checked all the pieces, describe the lot as unverified or incomplete rather than promising a complete set. A box, a built model or a photo alone does not prove every piece is included. Our bundle-selling guide helps you compare splitting the collection with selling one lot.
Step 1: sort what you have
- Sealed sets: leave them sealed. Do not open a box to check it.
- Complete sets: built or boxed, with all pieces and minifigures.
- Nearly complete sets: missing a few common pieces. Say exactly what is missing.
- Minifigures: often sold separately, especially from popular themes.
- Bulk: mixed bricks that do not belong to a set you can identify.
- Clone bricks: other brands mixed in. Look for the LEGO name on the studs and remove anything without it.
Step 2: find the set numbers
The set number is printed on the box and the instruction booklet. If you have neither, use distinctive pieces, printed parts and minifigures to search online set databases and LEGO's own instructions archive. Write down the number, the name and the theme for each set.
Step 3: check completeness
Rebuild or inventory each set against its instructions or an online parts list. Pay special attention to printed pieces, stickers, rare colors and minifigure accessories, which are the hardest to replace. Note whether stickers are applied and whether the instructions and box are included.
Step 4: clean safely
Dust built sets with a soft brush. For loose bricks, wash by hand in lukewarm water with mild dish soap, rinse and air dry on a towel. Avoid hot water, dishwashers and harsh chemicals, which can warp pieces or damage prints and stickers. Keep minifigures and sticker parts out of the wash if possible.
Step 5: gather boxes and paperwork
Boxes, instructions, unused sticker sheets and any receipts for retired sets add appeal for collectors. Flatten nothing; a creased box matters to some buyers.
Step 6: photograph it
- Each set built and complete, from the front and back, on a plain background.
- All minifigures lined up, front and back, with accessories.
- The box and instructions, showing the set number.
- Any missing, broken or discolored pieces.
- For bulk, a spread-out photo and the total weight.
Step 7: research the value
Retired sets, popular themes and rare minifigures can sell for far more than their size suggests, and the same set sells differently sealed, complete or incomplete. Scan a set or minifigure with WorthAI to identify it and see an estimated worth with a range, a suggested asking price, a reading of buyer demand and the marketplace listings it found. Add a photo of the box or instructions if it asks, or tap Refine Result. Then check recent sold prices for the same set number and the same condition.
Step 8: choose where to sell
- General marketplaces: the widest audience for sets and minifigures.
- LEGO marketplaces and fan groups: specialist buyers who know set numbers and parts.
- Local selling: good for large built sets and bulk bins that are expensive to ship.
- Toy stores and resellers: may buy collections quickly, usually for less.
Selling valuable minifigures separately can bring more, but it leaves an incomplete set. Compare both before you split anything.
Step 9: write the listing
Start with LEGO, the theme, the set number and name, then "complete", "sealed" or "incomplete". Our listing title builder helps. In the description, list missing parts, applied stickers, discoloration, whether minifigures and instructions are included, and whether the set is built.
Step 10: price it and count the fees
Price from recent sales of the same set and condition. Bulk is usually sold by weight or lot. Use the resale profit calculator to check your take-home after fees and the shipping cost of heavy boxes.
Step 11: ship or meet safely
Take built sets apart into labeled bags by build stage unless the buyer wants them built. Ship sealed sets in a larger box with padding so corners are not crushed. For local sales, meet in a public place and let the buyer check the set.
After the sale
Keep your photos and parts notes until the sale is final, in case a buyer reports a missing piece.
Common mistakes
- Opening sealed sets to check the contents.
- Calling a set complete without checking it against the instructions.
- Leaving clone bricks mixed in with genuine LEGO.
Frequently asked questions
Is it better to sell LEGO as sets or in bulk?
Complete sets usually bring more than the same pieces sold as bulk, but rebuilding takes time. Bulk is quicker for mixed bricks you cannot match to a set.
Should I open a sealed LEGO set to check it?
No. Sealed sets appeal to collectors because they are unopened. Opening the box usually lowers their appeal.
How do I find a LEGO set number without the box?
Check the instruction booklet, or search online set databases using distinctive printed pieces, minifigures and the theme.