The level of your personal allowance depends on your age and income. In 2013-14 if you were born on or after the 6 April 1948 and have an income of less than £100,000 then your personal allowance is £9,440. The personal allowance is reduced by £1 for every £2 of income above £100,000.
Those born before the 6 April 1948 have a personal allowance of £10,500 and those that are 75 and over have a personal allowance of £10,660 as long as their income is below a set limit. The limit is £26,100 in 13-14, the allowance is reduced by £1 for every £2 of income above this limit, The age related allowance is not reduced to below the standard personal allowance unless income is above £100,000. Eventually the higher age allowance will be phased out as it has been frozen until the standard personal allowance has reached the same level.
Blind people can claim an extra personal allowance of £2,160 and there are no age or income restrictions. Married couples, or partners in a civil partnership have an allowance if one partner was born before 6 April 1935. The level of allowance depends on the level of income and the date of the marriage or civil partnership. See http://hmrc.gov.uk/incometax/married-allow.htm for more details.
If you run a family business, consider ways to maximise the use of your spouse’s or other family members’ personal allowances by employing them in the business. Care needs to be taken to ensure that employment complies with PAYE requirements, other legislation and that the employment can be justified for commercial reasons.