Calculating married couples allowance How?

147718

We are a married couple age 79
My wife is a non tax payer
I understand that for 2011 2012 the married couples allowance is £7295 and yet my tax code document for this period shows £3648
How is the £3648 calculated

The allowance for 2012 2013 is £7705 but I have not yet received updated tax code

Can any one help please
147718

mrkbrrws

Married couples allowance is actually only a reduction in your tax of 10% x £7,295 = £729.50.

Assuming you are a basic rate taxpayer, the tax code gives you this allowance by calculating £729.50 / 20% = £3,647.50

Rounded up shown as £3,648.

147718

Thank you very much mrkbrrws
I now understand it and will able to check it out when I get my new tax code for 2012/2013
Thank you
147718