I agree fully with CC,
having dealt with the IR (now HMRC) on several tax issues, including training costs, I can support the view that you interests are not best served by going directly to them.
You are under absolutely no obligation to contact them, as your tax affairs are to date in order (I assume), so in your own time speak to an appropriate, experienced tax advisor. Then take the actions that are best suited to YOU not the HMRC.
If you speak to the revenue direct you will speak to a relatively low ranking Officer with no appropriate experience. His advice will be skewed to achieve IR income, and thus a better end of year Personnel Report for himself.