Need help please tax question

hattermadas

I have, like many I suppose received a tax calculation from the inland revenue today, saying I owe them £400 from tax years 2008 -2009.
I can see where they are coming from but, my problem or query if you like is this, at this time I was on incapacity benefit and still am now but, in Nov 2008 I went to work on what is called permitted work where you can work up to 16 hours a week without it affecting your benefits. It is a way to get back into work and can be done for upto a year.
I did this and left in the Oct the following year. I had to fill out all forms with the jobcentre who informed the said employer what I was doing which then I would have thought made them realise that they had to deduct the right amount of tax.
They obviously didn't and reading on the website it does state that I can write in to hmrc and tell them this but, surely it will be my word against theirs as I have no proof of this. Where do I stand, is there anyone who you think could help? I certainly wont be able to fork out £400 and if they allow monthly payments what will they take?
I certainly didn't expect this when it all blew up and am in quite a state about what to do.

anniecave

Have you checked all their figures are correct? What taxable benefits did you received during the tax year(s)? What income did you receive from the employment? Do they have the correct figures?

If you start work, it just depends on whether the payroll person has been given the correct information. They should not have taken any information off anyone else, you should have given them a p45 (if you were on any previous taxable benefits). Never assume tax is correct!