If your net earnings - that is, your profits after deducting expenses - are under a certain level, you can apply for exception.

In 2002/03 the level is £4,025. You can still choose to pay Class 2 contributions if you want to protect your benefits entitlement. See leaflet CA02 National Insurance contributions for self-employed people with small earnings, or contact your local Tax Office.

Until 5 April 1977, married women could choose to pay a reduced amount of contributions which did not count for benefits or a pension. This option is no longer available. But if, before 12 May 1977, you chose to pay the reduced amount, you can continue to do so unless

• your marriage ends in divorce or is annulled,or
• your Widow's/Bereavement Benefit ends for a reason other than remarriage, or
• you are widowed and do not qualify for Widow's/Bereavement Benefit, or
• you have not been liable to pay National Insurance contributions for any two consecutive tax years after 5 April 1978 and you have not been self-employed in those tax years.
  

If you've kept the reduced contribution option, you should hold a Certificate of Election (form CA270). If you do not have this, or it is out of date, contact the Inland Revenue National Insurance Contributions Office, Class 1 Caseworker Section, Longbenton, Newcastle upon Tyne, NE98 1ZZ.

If your certificate is current, you won't have to pay Class 2 contributions, but you will have to pay Class 4 contributions if your profits are high enough.
You can give up your right to pay reduced contributions if you wish, but you can't get it back again.

For more information ask for leaflet CA13 National Insurance Contributions for married women and leaflet CA09 National Insurance contributions for widows. See leaflet ca09 or leaflet ca13, or contact your local Tax Office. You'll find their number in the local phone book.

You don't have to pay Class 2 contributions after you reach state pension age, even if you haven't retired. You do not pay Class 4 contributions from the tax year following the year you reach pension age.

If you are sick, you can claim Incapacity Benefit from the Benefits Agency (or Social Security Office in Northern Ireland). Remember, they will ask for medical evidence.

You do not have to pay National Insurance contributions for complete weeks (Sunday to Saturday) if you are

• incapable of work, even if you are not receiving any benefits
• getting Incapacity Benefit, Maternity Allowance, Unemployment Supplement to Industrial Injuries Benefit or War Disablement Benefit
  

However, if you are sick for only part of the week, you must still pay your contributions. If you also work for an employer, you should send them sick notes regularly, even if your employer pays you Statutory Sick Pay.

If you have more than one job, you may be able to postpone payment of your Class 2 and Class 4 contributions until the correct amount has been worked out after the end of the tax year. You can do this if you

• expect to be both employed and self-employed during the tax year
• expect your earnings as an employee to take your National Insurance contributions over the limits (see below), and
• believe that your total National Insurance contributions liability will be more than £10 above the maximum limits (see below)
  

For the 2000/01 tax year, if you can show that you are likely to pay more than a total of

• £1,746.45 in Class 1, Class 2 and Class 4 contributions, you can ask to defer your Class 4 contributions
• £2,432.70 in Class 1 and Class 2 contributions, you can also ask to defer your Class 2 contributions

If your contributions are postponed, the calculation and collection of any Class 4 contributions will be transferred from your Tax Office to the Inland Revenue National Insurance Contributions Office. Your Tax Office will supply the Contributions Office with a certificate of your profits and gains, and the Contributions Office will let the Tax Office know when payment has been received.

For the 2000/01 tax year, if you have paid more than

• £2,435.76 in Class 1 contributions at the standard rate, you may be able to get a refund of overpaid Class 1 contributions
• £2,435.76 in Class 1 contributions at the standard rate and Class 2 contributions, you may be able to get a refund of overpaid Class 2 contributions
• £1,749.51 in Class 1, Class 2 and Class 4 contributions, you may be able to get a refund of overpaid Class 4 contributions
  

If you have paid contributions at non-standard rates, for example at the contracted out or married women's reduced rate, the Inland Revenue will convert any Class 1 contributions to the standard rate to work out if you have paid too much. Your employer's National Insurance contributions are not counted.