Short answer. No. Republic Act No. 6809, which lowered the age of majority from 21 to 18, expressly protects instruments made before it took effect. Existing wills, donations and insurance policies with provisions favourable to minors do not retroact to the prejudice of the person they were meant to benefit.
What the law says
existing wills, bequests, donations, grants, insurance policies and similar instruments containing references and provisions favorable to minors will not retroact to their prejudice
RA 6809, Section 4 — Existing Instruments Protected. Read the full provision →
The saving clause
When RA 6809 lowered the age of majority, it created a real risk: documents drafted on the assumption that a person stayed a minor until 21 might suddenly be read differently once majority arrived at 18. This provision heads that off. It states that existing wills, bequests, donations, grants, insurance policies and similar instruments containing references and provisions favorable to minors will not retroact to their prejudice. In plain terms, the change in the law is not allowed to reach back and strip a young beneficiary of an advantage that an older document deliberately gave them.
What 'shall not retroact to their prejudice' means
Laws generally apply going forward, and this clause makes that principle concrete for a specific class of documents. If a will or policy set a benefit to run until the beneficiary reached 21, the mere fact that majority is now 18 does not automatically cut the benefit short where doing so would harm the beneficiary. The instrument is read to preserve the favourable term. The protection is one-directional: it guards against prejudice. It is not a tool to enlarge a benefit, only to prevent the new age rule from shrinking one that was already granted.
Which documents are covered
The provision lists wills, bequests, donations, grants and insurance policies, and then adds "and similar instruments," so the shield is not limited to those exact four. The common thread is a document that contains references or provisions favorable to minors. If the arrangement was set up with a young person's benefit in mind and keyed to the old age of majority, it falls within the protection. Ordinary contracts that merely happen to involve a young party, without any minor-favourable provision, raise a different question and are not the target of this clause.
What this does not do
The clause protects the terms of pre-existing instruments; it does not freeze a person's legal capacity. For acts going forward — signing new contracts, suing, managing property — an 18-year-old is now of full age and is treated as an adult. So a young person keeps the favourable provisions written into an old will or policy, yet also gains full capacity to act. If you are unsure whether a specific clause in an older document is affected, the wording of that clause, read against this saving rule, is where the answer lies.