Changing of last name after the marriage
When you marry, you are free to keep your own family name or take your husband's name, Give some careful thought to what name feels best for you. You can save yourself considerable time and trouble by making sure you are happy with your choice of name before you change any records. The name changing method is so simple. You have to take your nikahnama (Marriage Certificate) and your old original CNIC with the father name and go to the NADRA office. You will be issued new CNIC with your new family name and husband name instead of father name. And after the CNIC you can get your new passport also.
Changing of last name after the Divorce
The same procedure you have to adopt for changing your name and getting your CNIC & passport with your father name after your divorce. When you get divorce / Khulla from the court or your husband pronounce you divorce then it will be mandatory for you to change your name and have to get new CNIC and Passport with your old name and with your father name. For this you have to visit NADRA office for CNIC and Passport office for Passport along with court decree of divorce / divorce deed and NADRA confirmation certificate that you have got divorce or divorce has been given to you.
Changing of name in other cases
In other cases if you want to change your child name before 18 years/age of majority that will be easy. You have to give the affidavit and get new birth certificate and in this way you can also change your child name in the educational institutions. But after the age of 18 years it will be very difficult to change the name without any cogent reason. However if you have sufficient prove that the name has been written wrong then you can change your name but for this you have to file suit in the court. And upon the court decree you will be able to change the name in the relevant Govt. records. You may also apply the interior ministry for the changing the name and if the satisfy then it will be published in the official gazette.