To qualify for extra payments, you have to meet all of these conditions:
Disadvantage test – To receive the disability element of WTC, claimants must have a physical or mental disability, which puts them at a disadvantage of getting a job. Disadvantage is assessed by the disadvantage test; a list of disabling behaviours or limitations.
The amount of money received from tax credits is dependent on a person’s gross annual income. As income rises, the amount of tax credits reduces.
Tax credits have a number of elements, such as childcare and disability; each element adds to the total tax credit paid. In working out how much to pay in tax credits, HM Revenue and Customs add up all the elements that a person is eligible for. This is then set against the amount of income they have. If their income is above a certain level, then the amount paid in tax credits is tapered away.
Consequently, it is possible for a person to be eligible for tax credits but have it tapered away due to their income. As a result not all of those eligible for WTC and the disability element will actually be entitled and positively benefiting from a claim in monetary terms because their income is such that it has been tapered away.
Visit: http://www.hmrc.gov.uk/taxcredits/start/who qualifies/workingtaxcredit/disability.htm for more information.