Found this article:

The Revenue is under fire for its policy towards individuals who actively deal in shares.

The Times reports that active traders risk surprise tax bills because they may be treated as sole-trading businesses rather than as private investors. However, some regular share dealers who say they would prefer to be taxed as a business are being denied the chance by the Revenue.

The Times cites the example of Sion Roberts, who has been dealing actively in shares since 2001, but has been refused sole trader status by the Revenue. He told the paper: "I have been dealing as many as three or four times a day and have notched up turnover of several million pounds a year. I have even set up my own dealing company and regard myself as a sole trader but the Inland Revenue insists that I am a private individual making capital gains."

Mr. Roberts added: "In the past two financial years I have made some substantial losses which, if a sole trader, I could offset against other income. As an individual I can only offset these against capital gains, which have been few and far between."

A Revenue spokesman explained: "Our general standpoint is that active traders are considered to be individuals making capital gains. It is up to those who wish to be classified as sole traders to prove that they do not fall within the category of individuals making capital gains. This has been our position for some time and we are not moving the goalposts on this."

Maurice Fitzpatrick of Numerica questioned whether the Revenue's dogmatic approach might change in a bull market. (As many who did make money in the last bull market found!!!!!)

Has this effected anyone?

Revenue spokesman's comment tallies with my local inspector's comment. It's up to me to prove I am a business (should I wish to be taxed accordingly), rather than having to prove I'm not (should I wish cgt to apply instead). It suits me to be an individual paying cgt, so I am happy with that attitude. But when i asked if there was a level of activity beyond which they would insist on regarding my activities as a business, they said there is no specific level. Nor did the question of whether or not share trading is my main source of income bother them.

PS: I am quoting my own local tax inspector. Yours may take a different approach.