Inland Revenue offices can only give general explanations about how much jobseeker's allowance (JSA) is taxable.
If a taxpayer wants to discuss how much of any benefit is
taxable you should refer the enquiry to the appropriate Benefit
Office or Jobcentre. That office will know how the taxpayer's
benefit was made up and so be in a position to give a detailed
explanation.
Also it is the Benefit Office or Jobcentre that initiates the
special appeals process for JSA. In most cases this involves the
taxpayer making an objection and an appeal at the relevant times.
This is explained at
EIM76301 to EIM76309.