ANNEX A: Background on National Insurance for the self-employed
2.The definition of self-employed for National Insurance purposes is a person who “is gainfully employed” in a trade, business, profession, office or vocation other than as an employed earner. The Act proposes no change to the current definition of a self-employed earner for National Insurance purposes.
3.All self-employed earners in Great Britain and Northern Ireland are required to notify HMRC of the start and end dates of their self-employment and are liable for weekly Class 2 contributions unless they are excepted (see below) or exempt(2) from payment. If they have UK profits that are chargeable to tax as trading income, they are also liable for Class 4 NICs on an annual basis(3).