It's fairly commonplace for remortgages to take place during IVA's. This might result, for example, from the end of a fixed/discounted period and the increased cost involved in going onto the lenders Standard Variable Rate.
It might also present an opportunity to switch from a repayment basis to interest only and potentially reduce the monthly cost (though of course the balance of the mortgage would not reduce if this were done).
Another reason might be that a better deal is available due to credit status. If someone had taken out a mortgage prior to entering an IVA (and during serious credit difficulties) it's possible that the rate would be higher than that available for an individual who has conducted their IVA well for a year or two since that difficulty.
It would be wise to speak to your IP first and then find an independent mortgage broker who specialises in mortgages where credit difficulties do or have existed.
The impact on the Year 4 remortgage would only be for any associated remortgaging fees (so long as the new mortgage is for no more than the old one).
Andrew Graveson
Bright Oak
andrew@brightoak.co.uk
www.brightoak.co.uk