National insurance tax
As the United Kingdom has a national healthcare system called the NHS, it also needs some sources of money besides the regular forms of taxes, which are mainly used for other different kinds of goals, to finance the healtcare system.
In order to do this a special form of tax called the national insurance is in effect since 1911, which basically covers the social security contributions for the employers and their employees for the state. The payment is based on a weekly system with the amount of the contribution determined by a record for every individual and by the classes of contribution which basically mean different rates of tax for every single class. In some special cases for unemployed or disabled people the payments for the national insurance contribution is made in one lump sum transaction, while self-employed people, similarly to companies are taxed based on profits in the current fiscal year.
There are four classes for companies, employees and self-employed in the UK with tax rates ranging from zero to 11% for employees and zero to 12,8% for employers. Corporate tax is at a zero rate up to an amount of income called the Lower Earnings Limit or LEL.

