I have a questions guys.
If I'm a supplementary line, and I want to buy, say the new iPhone 5S. Do I need to bring along the Principal line owner?

Thanks for the quick answer.
This comes to my next question ( not very clear on Maxis lines ), is there any advantages for main and supp line?
I was using iValue iinm, but since seldom call each other so thinking of changing plan.
If I am buying the iPhone 5S, and i bring main line owner as well , wouldn't the plan change as well? Since I'm following the contract plan and not the original supp plan. And that would bring me out of the main-supp line to become a main line myself?