shortened legal name in legal documents

Hi. Like any other Filipino child, I was blesed with two names. Technicaly, I have two first names and a surname. As I grew up, I usually used my first given name and my surname in all of my identifications. But my NSO still has that second given name.
Today, my aunt requested me to be her co-depositor in two banks. As in any document that I filled, I gave my first name and my surname (as it appears on the I.D. given to the banks). Seeing this, my aunt was horrified to learn that I didn't use my second given name. She says that I should have used my full legal name in all documents that I carry.
I would like to ask if there are any consequences (serious or not) of my practice of dropping off the second given name in lieu of the transactions and contracts that I entered.

Thanks in advance.

the law requires you to use the name that is registered on your birth certificate. complications will be getting a passport, visa, nbi clearance, and applying to take a government exam, etc.

i don't believe it will seriously affect any of your transactions and contracts.

Atty. what if there are already government issued id's bearing only the first given name.. and it does not include the second name how can it be corrected?

bring your birth certificate to the the issuer of the IDs and explain

Lastly atty, what if the said documents where filed in the US bearing only the first given name. For purposes of migrating to US, what can I do to prove that the name appearing in my birth certificate and the name appearing in my other documents refer to the same person?

for that, you should ask the US embassy how to notify them of the change and what documents they will require.

Thank you and God bless!