Q:
Applying game code to Trial Account?
A:
head on over to https://register.guildwars2.com to register your serial code. Put in the new code and when you are presented with the question “Do you have a Guild Wars account?” be sure to select “Yes” and enter your login information for Guild Wars 2. Then, be sure to put in the exact same information that you did the first time on the second page of registration. Once your registration is complete, your new code will stack on top of the old one, giving you an active serial code with pre-purchase bonuses. Please note that the last four digits of your display name may change. This is a known anomaly that we are currently working on a fix for. This does not affect your account in any way aside from having different digits following your display name.
This is the reply i got off support when i asked the same question.
Also i did it to my lads account so i know it works.
Ok, Tks for the help.
ArenaNet Communications Manager
Please remember to add the code to the account it’s intended for, not your own account.
I think in order to do that, you’d really need to get the code to your friend so he/she can log in and add it to the account.
And thanks for being such a considerate friend!
Communications Manager
Guild & Fansite Relations; In-Game Events
ArenaNet