It's currently listed as the first episode of Series 8 on the BBC website so it can stay for now as the website says there are five more episodes in the series.

If the listing changes when new episodes are released or if the next episode is also listed as S08E01, please submit a new report asking to move the Christmas episode to the specials.

@raze464 said:

If the listing changes when new episodes are released or if the next episode is also listed as S08E01, please submit a new report asking to move the Christmas episode to the specials.

Wouldn't it stay as S08E01 on TMDB even if the BBC change their data at a later date? For the same reason "The Devil of Christmas" episode is listed as a Special rather than in Season 3 (TMDB matches the data provided by the broadcasters website at the time each episode airs).

Normally, it should remains listed as the first episode of season 8. If the next episode is also listed by the BBC as S08E01, this new episode will just have to be listed aS08E02.

But, there is an exception. A season should at least have 2 episodes. So, if the next episodes are released as season 9, the single episode of season 8 will have to go to the specials and the season 9 will be numbered as season 8 here.

Another exception will be if they change their listing today (in the 24 hours after the broadcast), this will indicate the correction of a bug on their website.

Ok, but if this is the rule it needs to delete (at the moment) the special episode number 3, otherwise we have a duplicate.

@idro said:

Ok, but if this is the rule it needs to delete (at the moment) the special episode number 3, otherwise we have a duplicate.

Removed.

Next time, please, create your own report as this duplicate episode has been created after the processing of this report.