PIP underpaid me for 2 years 6 months... Will i also get working tax backdated

Bearspirit

Hi all.

I am currently in the process of having my pip taken to the tribunal, and during this process, pip relooked at my pip in case it didn't need to go to a tribunal. During this stage, they found an error on my account. I was supposed to have been awarded enhanced daily and standard mobility, but was awarded standard-standard which meant the owed me a backdated amount from 6th fFeb2016 = 31st August 2018. Obviously, this was a nice surprise when I received this letter but also shows just how bad dwp are at processing claims. I've had error after error...

My first question is; Would bringing this error to light at the tribunal be of benefit to my hearing which shows their incompetence?

Secondly; I currently get working tax credit for home self-employment work. I get the normal disability premium. Now that it's come to light i should have been on enhanced daily, and in turn, be on the severely disable element on working tax, will I get that backdated for the time period above? and would it be automatic or do i need to write into them?

Much appreciated