After 6 years I've been told my completion certificate should be in the post to me - hurray! But I enquired as to who informs the credit agencies as I thought they would - and have been told it'd the job of the creditors themselves? Is that guys?
The IP will inform the Insolvency Service, so you can be removed from the Register -- this can take up to three months. The Insolvency Service reports to the credit reference agencies who will them mark the IVA completed ( it will, however, stay on record until the 6th anniversary from the start. Creditors will have already registered your accounts as in default, with the default dates on or around the start of the IVA --- these defaults will drop off when they are 6 years old.
Have a read here, as well as the last entries on my blog (link is in my signature below) :