If you were born before 6 April 1938 you would normally be entitled to a personal allowance for 2015/16 of £10,660 as compared to the personal allowance for everybody else of £10,600. However, if your income is more than £27,700, you lose £1 of the additional £60 allowance for every £2 of income in excess of £27,600.
If you were born after 5 April 1938, your personal allowance will be £10,600 as it will be for those born after 5 April 1948. Take a look at section 2 here on personal allowances.
The married couple's allowance is available to those married couples or those in civil partnerships where one or both of the spouses or civil partners was born before 6 April 1935 but is restricted where the income is above the limit of £27,700.
You should call the tax office on the number here and ask them to amend the code if necessary.
I hope this helps but let me know if you have any further questions.