Hi SueG
At the moment it seems that most review forms for PIP are being sent out six months before the review date (not a year before). However, there has been no official word on this. I'm afraid you just have to wait.
Timescales are varying around the country for the whole process so it's had to speculate over the timescale. I'd wait to see when you receive your form.
BIS
Nothing on this board constitutes legal advice - always consult a professional about specific problems 
