ASSALAMUALAIKUM WA RAHMATULLAHI WA BARKATAHU RESPECTED SIR, MY FATHER DIDN'T PAY MEHR OF MY MOTHER NOW MY FATHER IS OLD AND MISSING FROM 5 YEARS. CAN I CAN PAY MEHR BEHALF OF MY FATHER PLEASE ADVICE JAZAK ALLAH KHAIR

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His Slave and Messenger.

The deferred Mahr (dowry) is a debt to which the husband is liable. Paying off this debt on behalf of your father is a good deed and act of worship; it is considered a form of dutifulness towards your father for which you shall be rewarded, by Allaah's permission, in this worldly life and the Hereafter. For further benefit, please refer to Fatwa 81637.

Allaah knows best.