The table below shows the current rates and earnings limits for National Insurance contributions, as determined by the HM Revenue & Customs, compared with those of the 2010-11 year. All figures are weekly unless stated otherwise.
There's one more class of National Insurance contribution; Class 3. These are fixed, voluntary contributions of between £12.60 per week that may be paid by people who would otherwise fail to qualify for retirement pension and some other kinds of benefit, usually because they have not yet contributed enough Class 1 or Class 2 contributions. This is not usually something that you as an employer have to be concerned about; it's a matter for the individual concerned to discuss with the HMRC.
If all this sounds complicated, it's not quite as bad as it sounds. Self-employed people pay Class 2 and (if they're earning enough) Class 4. Employed people pay Class 1 and their employers pay Class 1A. Anyone wanting to make up a deficit so that they can claim their pension pays Class 3. The varying rates for contracting out and other factors are all described in the leaflets and forms available from the HMRC, so as long as you - or your accountant - make sure that a payment and monitoring system is in place at the start of the financial year, National Insurance should be no more complicated than VAT calculations.
Rates and earnings limits for NI contributions
| Item | 2010/11 | 2011/12 |
| Lower Earnings Limit | £97 | £102 |
| Upper Earnings Limit | £844 | £817 |
| Primary Threshold | £110 | £139 |
| Secondary Threshold | £110 | £136 |
| Employee's contributions | 11% | 12% |
| Employee's Contracted-out Rebate | 1.6% | 1.6% |
| Married Women Reduced Rate | 4.85% | 5.85% |
| Employer's Contribution Rates | 12.8% | 13.8% |
| Employers' contracted-out rebate, salary-related schemes | 3.7% | 3.7% |
| Employers' contracted-out rebate, money-purchase schemes | 1.4% | 1.4% |
| Class 2 Self employed Contribution | £2.40 | £2.40 |
| Class 2 Small Earnings Exception | £5,075 per year | £5,315 per year |
| Special Class 2 rate for share fishermen | £3.05 | £3.15 |
| Special Class 2 rate for volunteer development workers | £4.85 | £5.10 |
| Class 3 rate | £12.05 | £12.60 |
| Class 4 Contributions - Upper Profits Limit | £43,875 per year | £42,475 per year |
| Class 4 Contributions - Lower Profits Limit | £5,715 per year | £7,225 per year |
| Class 4 rate between lower profits limit and upper profits limit | 8% | 9% |
| Class 4 rate above upper profits limit | 1% | 2% |