I've been perusing BrickLink for a while, and I noticed that essentially all sets are listed with a "-1" after the LEGO set number. For example, Set 41164, Enchanted Treehouse is listed on BrickLink as 41164-1.

What's the purpose of the "-1", and more specifically, what would a "-2" or even "-3" set number represent?

  • Does it represent a version number (e.g. a revised or post-recall version of the set would be numbered 41164-2)?
  • Is this a country code?
  • Is it just a site-specific affectation?
  • Is it currently unused, but reserved for future use?

3 Answers 3


TLG hasn't always been particularly careful about their set numbering, so the community has taken to adding -1 to the end of the set number to handle cases where there may be duplicate set numbers used by TLG. For example, here's what we refer to as 8858-1:


And 8858-2:


As others have pointed out, this also helps to track minor adjustments to sets (re-releases, box differences, inventory adjustments, etc). Bricklink maintains a list of sets that are similar and have the same official set number but which are assigned unique suffixes for various reasons.

  • 2
    Mind blown that the later one was assigned -1 and the earlier one was assigned -2.
    – shoover
    Jun 23, 2020 at 3:32
  • 11
    That Engines Expert Builder Set looks really nice for such a limited number of pieces. I wish more modern sets would replicate mechanical engineering solutions like that with simple building blocks, instead of applying excessive attention to visual detail with weirdly shaped custom parts that are almost un-reusable in any other configuration.
    – Will
    Jun 23, 2020 at 3:39
  • 1
    @Will Well, the weird parts mean people will buy more... it's the sad ugly truth.
    – Nelson
    Jun 23, 2020 at 9:30
  • 1
    @Will Mechanical engineering solutions like that with simple building blocks? In this case I highly recommend Yoshihito Isogawa's books and youtube channels. Definitely check them out if you don't know them already...
    – Uli
    Jun 23, 2020 at 17:04
  • Why is 8858-2 used for the older set? Is it just that 8858-1 was added to some database first? Personally I think it would be more sensible to omit the -1 until there's a numbering collision, or distinguish them by release release (e.g. "8858 (1980)" and "8858 (1994)").
    – jamesdlin
    Jun 24, 2020 at 4:28

As jncraton pointed out some numbers have been reused by different sets, however there are other cases too.

A good example is 10242 MINI Cooper. During production of this set TLG has decided to change the box from original squarish size, which is designated as 10242-1 on Bricklink

enter image description here

to rectangular version of the box, so Bricklink used 10242-2 to mark this change.

enter image description here

  • 1
    Same thing occurred for the box of 31313, but I don't think that BL knows that the box of 31313 changed, which is why you only see the original box design. I'll submit an inventory addition request. Jun 22, 2020 at 18:54
  • @mindstormsboi That's interesting. I have only heard of slight design change of outer sleeve. How did the change of dimensions you've mentioned affected the design of the inner sleeve? These must be different too then?
    – Alex
    Jun 22, 2020 at 19:14
  • Oh wait, I meant sleeve, you're right. BL doesn't seem to know about it though. Jun 22, 2020 at 19:15

In the 1980s, there was a major set adjustment to the Lego space sets , in North America. I know, because I have both sets. One is noted as -1 and the other -2, which actually has been helpful in sorting sets. It is arbitrary, and I don't see it as the first or second time the same part number used. But untill Lego group makes an adjustment, or creates an online catloge of all sets, I don't see brick links actions as objectionable.

  • 4
    Which sets are these? Also, I didn't say anything about objecting to it. Jun 23, 2020 at 13:41

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