Make mortgage overpayments don't switch

David from Clay Hall says: "Why is there no encouragement or educating borrowers that they can make voluntary overpayments (normally 10% of the mortgage balance in one year) to reduce their balance whilst maintaining the flexibility of reverting to an interest only payment in the event of a ''tight'' month around the holiday seasons etc.?

Surely this is a better alternative to the all or nothing scenario of capital & interest vs interest only where if borrowers are under financial pressure, being unable to make a full monthly capital & interest payment on just one occasion could wreck their credit file with the now unecessarily tight lending criterion, whereas so long as they make the interest payment on an interest only deal (althogh requiring discipline to make the voluntary payments) can save them from this irreparable scenario?"