Tax Calculation

Romans53

I need some advice regarding some correspondance I have received from HMRC.

I have had a P800 Tax Calculation regarding tax year 2011-12.

They say that I underpaid tax and are looking to collect it through 2013.

During 2011 I worked fulltime until Oct, then quit my job. I did sign on but only to ensure that my NI was still being paid. I then got a part time job from Nov until Oct 2012. This generally was more than the threshold to receive JSA but I still had to sign on, etc.
From Sept 2012 I gained new fulltime employment, told the Jobcentre and passed on all relevant forms to my new employer. I wasnt taxed from the start of this job until this month.
I received a tax refund in April 2012.

I am confused as to what I can do as during the time I was working part time any week that was ws more than the usual I was taxed, but generally my hours were too low to be taxed.

What can I do to rectify this? Is there anything I can do as surely if I had underpaid income tax they would have taken it from when I started a new employment

Romans53

Any advice guys?

CLAPTON

you need to give us the figures to make any sense of this

System

As a starting point I'd check the calculation is right. If I remember correctly the P800 doesn't show a breakdown of earnings etc from different sources.

Add up the pay from your 2011-12 P45 + 2011-12 P60 + JSA.

Does this match the P800?