HM Revenue & Customs have recently updated and clarified their guidance on training costs paid by the self-employed.
The general rule for whether the cost of a training course can be deducted from your self-employed profits is that it must be incurred wholly and exclusively for the purposes of the trade being carried out by the business at the time that the training is undertaken.
If you are self-employed, a training course that updates or provides expertise or knowledge in your existing business area will normally be deductible. This means that training on new skills or knowledge for you to keep up with changes in your industry, or to help you keep up with advances in technology can be allowable.
In addition, training on subjects that are ancillary to your main trade can be allowable too depending on the circumstances. As an example, a plumber who books a training course on bookkeeping or digital skills would likely be able to deduct the cost of those courses from his self-employed profits.
Where a training course is to give an individual skills to start a brand-new business, or to add a new, unrelated business area to their business, then HMRC view them as not allowable.
To see some examples of expenses and whether they are likely to be allowable or not please see: https://www.gov.uk/guidance/check-if-the-cost-of-training-could-be-an-allowable-business-expense