Consent of both parties is immaterial.
Petition for Nullity of Marriage can only be filed under certain circumstances including:
1. one of both spouses were minors (below 18 years old) at the time of the marriage;
2. Did not give consent to the marriage;
3. No marriage license;
4. The solemnizing officer (ang nagkasal) has no authority to do so;
5. No marriage ceremony (walang kasalan na naganap);
6. Either or both parties have psychological incapacity;
7. Others (I think not relevant anymore so I am not enumerating them here)
Annulment can only be filed when any of the following is present AT THE TIME OF THE CELEBRATION OF MARRIAGE (during the wedding ceremony):
1. Absence of Parental Consent when one or both spouses were between 18 and 21 (at the time of the marriage) and there was no parental consent form the parents/guardian;
2. Mental Illness of either or both spouses;
4. That the consent of either party was obtained by force, intimidation or undue influence (for example shotgun wedding);
5. One or the other party was physically incapable of consummating the marriage, and such incapacity continues and appears to be incurable (for example baog or cannot have sexual intercourse);
6. Either or both have sexually-transmitted-disease (STD) which is serious and seems to be incurable.
Petition for Nullity of marriage based on psychological incapacity is more costly.