If new installments of the same type are issued,SBK automatically rolls them over into the new installments.If u want to pay the difference and obtain the share then contact the bank upon expiary.Its usually not worth doing that unless there the shares have increased a great deal in price....Another thing that i have noticed is that on the loan stock,is that there are no further replacement installment being issued at this time.Only my opinion but i think it is better to sell them before expiary....In any case if u are not certain,contact them. OMO