In the Star Trek universe, Starfleet vessels have registry numbers that typically begin with the prefix NX or NCC. The most famous of these is NCC-1701, the registry number of the USS Enterprise and its successors.

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In-universe, these are assigned to starships roughly according to the order in which they are built and commissioned. (The successor Enterprises are an exception as they persist with the NCC-1701 registry, but with the addition of a letter suffix to distinguish them.)

Out-of-universe, do these registry numbers have any special significance? How were they chosen?

For instance, the USS Voyager is NCC-74656. It seems uninspired at first glance. Does the particular number 74656 have any hidden (or obvious) meaning? Why did the writers or creators choose it?

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On the other hand, were NCC-1701 and NCC-1864 (the latter being the registry of the USS Reliant) derived from the years 1701 and 1864, respectively? For the latter, the USS Reliance served in the American Civil War (as part of the Potomac Flotilla) and was scuttled in 1863. Is there any connection? Gene Roddenberry was known to be a war buff, and Nicholas Meyer (directed of The Wrath of Khan, in which the Reliant appeared) was a fan of naval themes.

Any interesting information about any registry numbers appearing in Star Trek would be great.

3 Answers 3


According to the wikia on Registry Numbers :

The most famous registry number, of course, is "NCC-1701" of the original USS Enterprise. It was chosen by Matt Jefferies, who was a pilot before joining the Star Trek staff, and based the registry number on 20th century aircraft registration codes. In the early 20th century, the letter "N" indicated a United States origin, and the letter "C" indicated a civilian aircraft. As American craft used NC and Soviet craft used CCCC, Jeffries combined the two as NCC.

His philosophy was, "If we do anything in space, we (Americans and Russians) have to do it together." H states the numbers "1701" stand for the 17th cruiser design, serial number #1. Also, upon choosing the Enterprise's registry number, Jeffries decided that the number should be easily readable, so he was careful to avoid numbers that could be confusing, such as 3, 6 and 8.

So it looks like the numbers were based on 20th century aircraft registration codes and the letters are a conglomeration of US and Soviet aircraft country-of-origin codes.

  • 2
    Huh. Fascinating.
    – Nerrolken
    Jun 11, 2015 at 16:46
  • 5
    @Nerrolken: You misspelt "disappointing". Jun 11, 2015 at 17:53
  • 2
    "If we do anything in space, we (Americans and Russians) have to do it together." - could that possibly mean that "NCC" is actually a mixture of Latin and Cyrillic script? i.e. ... "NCС", or "NСС"? (assuming that the Soviet craft actually used "СССС", not "CCCC") Jun 11, 2015 at 18:12
  • Considering they never use any cryllic anywhere else...
    – user16696
    Jun 12, 2015 at 18:03
  • 1
    @Daft : This is a great answer. I waited a while to accept it just to give some time to see if information about any other starships' registry numbers would surface. But it seems that 1701 is the only one with a (known) out-of-universe explanation. Thanks for tracking this down!
    – Praxis
    Jul 2, 2015 at 4:40

It seems to be a matter of category.

NCC seems to be used on standard vessels, such as Voyager, the TOS and later Enterprises, and a most other things. We saw it on every Intrepid and Galaxy class. We saw it on the Nova class starships. You name it, we generally saw it.

NX seems to be used on experimental vessels. Examples: In the season finale of season 4 of Voyager, the fake vessel the crew encountered was NX-01A, which didn't surprise them at all. Furthermore, the original NX class, from the ENT era, was experimental. Only 4 vessels were planned, and these were the first vessels of this speed category, so having them as experimental "at least officially" makes sense.

  • Thanks for weighing in on this. I appreciate your interest in my question. I think you have misread / misinterpreted it, however. I am not asking about the prefix part (NCC / NX) of the registry number, I am asking about the numerical part. 1701, 1864, 74656 --- what meaning to they have, if any?
    – Praxis
    Jun 19, 2015 at 17:37
  • I suspect they're simply unique numerical identifiers for the vessels. Jun 19, 2015 at 21:23
  • In-universe, that's exactly what they are. The question is about out-of-universe: do the numbers have any special significance for the writers / designers of the show?
    – Praxis
    Jun 19, 2015 at 22:26

NCC Stands for

The numbers are the hull numbers assigned to classes and given sequentially as they are constructedU.S.S .

Constitution class from TOS spanned hulls 1700 to 1799
The first ship off the line was the class ship U.S.S. Constitution, Naval Construction Contract-1700
Second off the line was U.S.S. Enterprise, Naval Construction Contract-1701.

NX stands for
Because, of course, the word experimental begins with the letter X

  • While interesting, this answer appears to be addressing the in-universe numbering convention; the OP is interested in the out-of-universe Oct 31, 2015 at 1:11
  • This is what the manual says. I do know the story that they were originally derived from aircraft country codes--which is true. It is also true that someone cleverly ages ago developed the usage you're referencing here after figuring out that the codes from aircraft country codes--which is true. But it is also true that someone cleverly ages ago developed the usage you're referencing here after figuring out that the codes had to mean SOMETHING and they got it into canon. So for decades as showrunners and technical advisers have learned, NCC=Naval Construction Contract and NX=Naval eXperiment. Dec 30, 2022 at 1:19
  • Remember that the Enterprise and the Columbia were both NX class and both were unique (two of the same spaceframes, very different innards), and they were the only two made before the Oberth class and the refits of the Daedelus class to use all the experimental tech in the two NX models. Dec 30, 2022 at 1:21

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