If you are applying for your first National ID card and your parents were unmarried at the time of your birth you can have both their surnames placed on your card as your surname, provided that you can show proof that either;
(1) you have used the name throughout your school life by way of a letter from the school or examination certificate (s) or
(2) show other form of ID such as a Passport.
However if you already are in possession of a valid National ID card under either parents surname but you wish to now carry both surnames on your ID , a Protocol of Deed or Deed Poll is required .