The Inland Revenue was, until April 2005, a department of the British Government responsible for the collection of direct taxation, including income tax, national insurance contributions, capital gains tax, inheritance tax, corporation tax, petroleum revenue tax and stamp duty. More recently, the Inland Revenue also administered the Tax Credits schemes, whereby monies, such as Working Tax Credit (WTC) and Child Tax Credit (CTC), are paid by the Government into a recipient's bank account or as part of their wages. The Inland Revenue was also responsible for the payment of child benefit.

National Insurance (NI) is a fundamental component of the welfare state in the United Kingdom. It acts as a form of social security, since payment of NI contributions establishes entitlement to certain state benefits for workers and their families.