A while back I seem to remember reading somewhere that doctors' letters and other supporting corres and information that you can enclose with a PIP form has to be less than 2 years old for them to take any notice of it, but I can't find the reference now.
I've just received my DLA to PIP application form and saw that it says that 'the supporting evidence you send doesn't need to be recent'. Have things changed with PIP re the 2 year restriction and, if so, would evidence from 2013 and earlier be taken into account (as my medical conditions haven't altered since then)?
The DWP tend to depreciate any evidence that is more than two years old, however, if you can show it's relevance to your problems now then it should still carry weight so if these are diagnosis letters for a life long condition then I would include, but as is the case for anything that you send, explain the relevance.
In my experience of cases, I have helped with - old relevant evidence has still carried weight.
BIS
Nothing on this board constitutes legal advice - always consult a professional about specific problems
The following user(s) said Thank You: nofuss , layla