Ah,
Milt and CT there's a flaw in the arguments I'd suggest - which I'm not saying the IR WILL make use of, only that they probably could if required : All taxpayers are to be treated equally - yes, those purely gambling for fun and profit are taxed as gamblers, those doing so consistently and earning a living thereby are taxed as if it is income. I'm STUNNED your accountant didn't spot this, equal treatment for identical people is what counts, that doesn't suggest for one moment that people put into different pigeonholes will be dealt with identically. There doesn't seem to be a dividing line here, I would suggest that what will happen in practise is that an inspector of some sort will look at the figures and pronounce a verdict - proving you are identical to Mr X and should have been treated differently (as Mr X was) might be a bit difficult. I wouldn't doubt that precedent etc comes into play, but it seems to me to be the sort of area where you end up vindicated and very poor.
having put 5% of SB and Horse racing gamblers into the 'pro gambler' bracket and taxed them as income, yet leaving the other 95% under 'mug punter' and tadxing them on non-existent gains does not cause any problem for the IR at all - they don't have to tolerate a winning minority, just classify them differently.
This IS a rather bleak version of the possibilities - I suspect you can win for a good while before they start moving the goalposts around, but I've had my accountant warning me already at a level I consider quite paltry, phrased as 'not a problem yet, but it might be one year' so I think I agree with Bonsai to a degree here - this area is really a bit of a minefield, requires serious research to be vaguely sure of the position, and the IR can make the rules up a bit as they go along so a consiste t winner MIGHT have to invest quite heavily, one day, in tax fighting legal efforts.
Overall I suspect that the real answer is to move somewhere with looser tax laws (Montenegro? Is that the place?) if you are making significant and steady profits.
All the best anyway, 'where to bury the gold' is a problem we should all have
Dave