Ultimately it depends on the cut off score for QUB's internal points system. You should not be concerned about your UKCAT score, but rather, your UKCAT score
in relation to the rest of your application
You calculate your points score by ranking your top 9 GCSEs, where an A* is worth 4 points, A is worth 3 points, B is 2 and C is 1. This brings you to score out of 36.
You then add your GCSE points score to your UKCAT score, which is out of 6. Therefore, in total, your points score is out of 42.
Banding of UKCAT Scores Points
1200 – 1899 = 0
1900 – 2099 = 1
2100 – 2299 = 2
2300 – 2499 = 3
2500 – 2699 = 4
2700 – 2899 = 5
2900 – 3600 = 6
The cut off for interview has never been higher than 38 points. Last year, I think it was 30 points for some reason.
All in all it is very clear that, whilst the UKCAT is extremely important and shouldn't be neglected, GCSE point score contribute the majority of the points, therefore your GCSE point score is far more important than your UKCAT score.
(This makes sense, since the UKCAT only represents 2 hours of your life whereas GCSEs show how well you've performed in the long run, over a variety of subjects and how dedicated you are to your studies. UKCAT only tests aptitude and it's multiple choice so has its limitations too as 1) its not a control test, since people do different exams so some may have easier/ harder questions and 2) people might, by fluke, get really high scores just by guessing whereas its harder to get 9A* GCSE just by fluke therefore justifying why they weight GCSEs more heavily, to show you can cope with the prolonged academic intensity of medicine)
Your UKCAT score isn't bad, provided your academic point score makes up for it. I'd say if you have around 38 or above, you're fairly safe because if the cut off rises to 39 or 40, it means everyone they interview has like 9A* GCSE and UKCAT of 650 or so, which is quite high. The cut off has never been higher than 38.
Also I called the admissions team and they said that the combined UKCAT and GCSE point score is just to get to the interview stage. Once you achieve an interview, it is the interview alone which determines whether or not you get an offer. So someone with 42/42 points has no advantage over someone with, say, 38/42 points at the interview stage.
It is also worth mentioning that QUB doesn't look at the SJT band for the UKCAT however, in borderline cases (i.e they don't have many places left to make an offer and are trying to differentiate between similar performing candidates at interview to fill up the few places remaining), they may look at SJT, and/or extra GCSE A*/A grades not included in the 9 which they looked at before interview.
I hope this was helpful, and I urge you not to worry. If your academics are good then you actually make for a great candidate