Do I Need Set Numbers to Sell My LEGO?

This is the most common thing people get stuck on, and it stops far more collections being valued than it should. It is genuinely easier than it looks.

Where the number is

On the front of the box, usually in a corner, printed near the age guide and the piece count. It is four to seven digits, with no letters. On older boxes it can be smaller and in a different corner, and on very small sets and polybags it is often on the back.

Why that number does all the work

It identifies exactly one product. From it, anybody can tell what the set is, what year it came out, how big it is, when it stopped being made and what it is currently selling for. That is why you do not need to know anything about LEGO to write a usable list, and why a list of numbers is worth more than a list of names.

When the number has worn off

It happens, particularly on boxes that have been handled or stored badly. It is not a problem.

1. Describe the box: the theme if you recognise it, the main model, roughly how big the box is.
2. Take a photo of the front. That is usually enough on its own.
3. Note anything printed on the back, including a barcode if it is legible.
4. Send it with the rest of the list and let somebody who handles these daily work it out.

If writing a list is impractical

For a very large collection, photographing the stacks is a perfectly reasonable alternative. Lay them out so the fronts are visible, take a few clear photos in good light, and send those. It is slower to price than a list of numbers, but it is far better than not asking at all.

What not to do

• Do not open a box to see what is inside. The number is on the outside and the seal is most of the value.
• Do not rub at a worn number to make it clearer. You will take the print off.
• Do not guess a number. A wrong number produces a wrong price and it has to be unpicked later.
• Do not leave out the boxes you think are worthless. Some of the plainest boxes are the interesting ones.

How much detail is enough

Set number and how many of each is enough to price a collection properly. Adding a note about the worst box makes the figure more accurate. Anything beyond that is helpful but not necessary, and a list that takes you an hour is worth far more than a perfect one you never finish.

Common questions

What people ask before sending a list.

What if I only have half the numbers?

Send what you have and photograph the rest. A partial list is a perfectly normal starting point and we can work from it.

Does the barcode help?

Sometimes, but the set number is more reliable. If the set number is gone, a photo of the front is usually a faster route than the barcode.

Do I need to say what condition each box is in?

Not each one. Describe the worst box in the collection and mention anything that has been in sunlight or damp. That is enough to price accurately.

What if I have hundreds of boxes?

Photos of the stacks are fine, or a spreadsheet if you already have one. There is a box on the form that will read a spreadsheet and pull the numbers out for you.

Turning a pile of boxes into a list without losing a day

For a large collection the job is logistics rather than knowledge. A method that works:

1. Clear a table or a stretch of floor and work in batches of twenty.
2. Stand the boxes so the fronts face you. You are only reading one number per box.
3. Say the numbers into your phone as a voice note rather than writing them. It is roughly three times faster.
4. Do quantities at the end by counting duplicates, rather than tallying as you go.
5. Put anything you cannot read into a separate pile and photograph that pile at the end.

Written by Peter Pilling, BuyMyBricks, 26 September 2026. LEGO® is a trademark of the LEGO Group, which does not sponsor, authorise or endorse this site. A more complete list produces a more accurate figure, but an incomplete one is always worth sending.