The rates paid by employers and employees are all going to rise by 1% from April 2011. People earning less than £20,000 will be immune. Unlike income tax, NIC discriminates between employed and self-employed with lower rates for the self-employed.

The changes are estimated to yield an additional £6.5 billion between 2011 and 2013. This dwarfs the £550 million expected to be raised by the much publicized one-off . ...