Is Self-certification of the Experience Permissible/Admissible?

[Kay2]

Can anybody tell me whether self-certification will be accepted by the CIC?

By self-certification I mean: writing an experience certificate for yourself, by yourself. That is in the case of a self-employed person, who doesn't have an 'incorporated entity' possessing a logo and letterhead etc. and doesn't have too many clients (certainly not the clients who would have written communication) capable of giving out references. If such a self-employed person writes an oath and declares the details of their experience and produces the accounts and tax documents, would that be enough to claim points for experience?