Wrong details on a P60, issued by the DWP

Hi All,

We have a client who we helped to get some housing costs backdated with her claim to ESA, the period of arrears stretched back into 2018/19.

Based on the above the DWP reissued the P60, however the DWP have included amounts, as taxable, that are above the CESA element i.e. they have included some of the housing cost element and or the IRESA element.

We understood that only the CESA element of ESA was taxable?

My client is very anxious about this, and has sent several letters to the DWP, with no response other than a further P60 being issued with an increased amount of taxable income for 2018/19

Is there any route to appeal/challenge the P60 and if so would this be directed at the DWP or HMRC?

Any help/advice much appreciated

As ever, thanks in advance.