If it is to do with PPI and an IVA you should not need this as far as I am aware.
Sharing from experiences of dealing with debt
The greatness of a man is not in how much wealth he acquires, but in his integrity and his ability to affect those around him positively.
Bob Marley. http://kallis3.blogs.iva.co.uk
As the assignment is a transfer of an interest ( in this case the PPI)it is a "Deed" and it should be witnessed, although this convention is not always adhered to these days.
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014