Hi, I am new and have found the forum very informative, I just wanted to offer my timeline for PIP as some might find it helpful. Not sure if this makes a difference but we are London based.
I applied on behalf of my child on 20th November over the phone, I received documents about a week later. I completed the documents and included a copy of my daughters recent medical review from CAMHS, this included background history, current health, diagnosis, medication, next steps and returned the form on 16th December. I started to worry after sending it that I did not write enough information, as I only wrote a paragraph for each question, but I was to the point.
On 5th Feb we had the assessment over the phone which I did on my Childs behalf, it was very straightforward and lasted approx. 10 minutes. They wanted extra information about my child preparing a meal and mobility.
On 14th Feb I had a call to confirm bank details and over the phone they said that my child was entitled, High rate daily living and standard mobility and what the backdated amount was.
I hope this helps!