Spectrum Serial Numbers

Regarding the ZX Spectrum Serial Numbers Database please see here.


Number found on a ZX Spectrum is a serial number of the machine which indicates important information about the unit. Each given serial number is unique although mistakes can happen which result in two or more different machines bearing identical number. This is down to mechanical issues of the stamping equipment used and such phenomenon is very rare to observe. There is a possibility, however, that your ZX Spectrum has a long lost twin out there in the wild.

Serial numbers can generally be found on the bottom of the case although certain factories would hide the numbers inside the case. Some ZX Spectrums aren’t assigned serial numbers at all.

Standard format used for serial numbers is ZZZ-XXXXXX where:
– Z is a factory ID where the ZX Spectrum has been assembled. Often it’s also pointing to a period when the Spectrum was allocated its number.
Y is a sequential number used to indicate the order in which the ZX Spectrum rolled off the production line. Number YYYYYY is linked to the ZZZ prefix.
The correct order is: 001-123456 … 001-123457 … 001-123458 …
The incorrect order is: 001-123456 … S01-123457 … 001-123458 …
The incorrect order is: 001-123456 … 028-123457 … 001-123458 …


There were 4 main factories which manufactured ZX Spectrum computers in Sinclair era for British market.

  • Main Timex Factory in Dundee (Scotland, UK) where ZX Spectrum computers were first built. Prefix: 001-051; 101-151 The factory used colour coding indicating year of production:

    Green 1982/1983 Issues: 1, 2,3

    Red1983/1984  Issues: 3, 3B, 4A, 4B, 5, 6A

    Blue1984/1985  Issues: 3B, 4A, 4B, 6A

    The Timex factory was manufacturing the largest amount of ZX Spectrum computers. The first 675,000 Spectrums have fixed 001 prefix which then changes to 002, 003, etc.  to reflect week number thus ensuring continuity of the sequence while still only using 6 digits of the suffix.

    The plant was also assembling Sinclair ZX81 and Spectrum 128K UK Toastrack computers.
    Yellow1985/1986 Spectrum 128 versions: 6K, 6U, 9G
    A8-080030SAMSUNG CSC

  • Thorn EMI Datatech Factory in Feltham (England, UK)  has joined in ZX Spectrum computers manufacturing soon after to satisfy the market demand. Later also manufacturing Sinclair QL computers.
    D01 Issues: 2, 3, 3B, 4A (estimated 600,000 units made)

    48K, Issue 2Interface 1 font styleD01-033940D01-381236

    Machines assembled in this factory can be recognised by a small round sticker often appearing next to the serial number either in green (16K) or white (48K). Same type of round sticker but in grey colour also appears inside the case attached to the motherboard on top of the TV modulator lid or on the surface of the beeper.





    D03 Issues: Any. Prefix indicates the shell is used to hold a motherboard that has been rehoused or originates from a different factory.



  • Samsung Factory in Korea also manufacturing Sinclair QL computers.
    Prefix: S01 Issues: Samsung 3B and 4S (estimated 170,000 units made)
    Samsung Serial Number
    Samsung made machines can be recognised by the distinct green colour of the motherboards. Read more about Samsung-made Spectrums here.
Samsung 3B


Samsung 4S

Samsung 4S

  • AB Electronics Factory in Abercynon (Wales, UK) only manufactured Spectrum 48K+ computers and Sinclair ZX Spectrum Interfaces.  Prefix:
    A01, A02
    Issues: 4B, 6A (estimated 100,000 units made)

    A02/XXXXXX/AR: Any



Spectrum 16K/48K (Rubber Keys)



16K (green sticker)

48K (white sticker)

16K (green sticker)


48K (white sticker)


48K Issue 2


48K (shielded top)







48K (yellow board)



48K (NTSC)




Spectrum 48K+



Issue 6A

6A, Inves

Issue 6A, Inves


Version 2

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9 thoughts on “Spectrum Serial Numbers

  1. What happened to the ‘submit a serial number’ form you used to have? has it moved? have a small pile of machines to add to the list…


    • Unfortunately I had to remove it after I found out people were sending in incorrect numbers (not on purpose ,of course, but by mistake). I can only accept entries which I can verify via a photo myself. So at the moment, before I figure out another way, best to send me photos of the Speccys via email.


      • Doh, that’s a shame, never underestimate the ability of folk to goof things up eh, if I ever get around to it I’ll drop some photos, just bagged a nice blue keyed issue one recently, feels odd for it to be dressed in blue keys though!


        • I know what you mean, it almost feels like the keyboard doesn’t belong. It’s a popular misconception that issue 1 only has grey keys. So many times I see a Spectrums selling for a silly price just because of the grey keys even when the motherboard inside is issue 2. And at the same time some issue 1 Spectrums don’t get noticed because they have normal blue keys. Oh well, at least the latter can be picked up at a bargain price.


  2. Hi, im looking to pick up a 48k just to play games and enjoy. Is there any issues i should be avoiding? The samsung stuff etc. not interested in low ser numbers to speak of just want a proper spectrum like i used to have. Just doing a lot of research at the mo and came across your page, thanks steve.


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