Number range: 946 0000 to 946 0009
946-0421falls inside this range.
(Notice that the bulletin uses the post-PhONEday area code for London, not
Edit: As Martin McNulty has pointed out on Twitter, this is nonsense. The number doesn’t fall in this range. You can see the precursor of the block that Ofcom now reserves, but the number used in the episode is a combination of the two ranges. It’s got
946 from the 1999 bulletin, and
0421 from the range in the current guidance. (This is what I get for late night blogging!)
The previous bulletin, Numbering Bulletin 37 from November 1998, explains that Oftel was planning to assign some numbers for use in fiction, but hadn’t yet done so. Presumably they picked a bank of as-yet unallocated numbers, but I haven’t dug any further. It’s possible this number went somewhere in 1992 and then got unassigned, but it seems unlikely.
Now I know: this is a UK phone number with a period-accurate dialling code for inner London, drawn from a range of numbers reserved for fictional purposes shortly after the story is set.
This sort of trivia research is fun and it appeals to my specific brand of nerdery, and speaks to the attention to detail in the production design, but it doesn’t pass for serious analysis.
If you want more in-depth discussion of For All Mankind season 3 (which I’m really enjoying), I like the NASA Vending Machine podcast and the articles on Fangirlish.