Short answer. The notice is defective. Article 283 of the Labor Code requires written notice served on both the workers and the labour department at least one month before the intended date. Two weeks does not comply, and paying separation pay does not cure the shortfall — they are separate requirements.
What the law says
by serving a written notice on the workers and the Ministry of Labor and Employment at least one (1) month before the intended date thereof
Labor Code, Article 283 — Closure And Personnel Reduction. Read the full provision →
Two notices, one deadline
The requirement has three parts that employers routinely collapse into one. The notice must be written; it must go to the workers and the Ministry of Labor and Employment — the article still uses the department's former name — and it must be served at least one (1) month before the intended date thereof. So the clock runs backwards from the day the employment is to end, and both recipients must be served. A memo circulated internally, or handed to staff while nothing is filed with the department, satisfies neither half of the requirement.
Short notice and a false ground are different defects
It helps to keep the two questions apart, because they are assessed separately. The first is whether the authorised ground the employer invoked — retrenchment to prevent losses, redundancy, installation of labour-saving devices, or closure — genuinely existed. The second is whether the procedure the article prescribes was followed. A flawless one-month notice does not turn a fabricated retrenchment into a valid one, and a genuine retrenchment is not erased by a fortnight's notice. What a short notice does is put the employer in breach of a requirement the Code states in mandatory terms.
Separation pay does not buy the notice period
Employers often treat two weeks' notice plus a payout as a package, on the view that money in hand is what the employee actually wanted. The article does not read that way. It states the notice requirement in one breath and the separation pay entitlements in the next, as distinct obligations attaching to the same termination. Being paid what you are owed does not mean you were given the notice you were owed. For the same reason, do not assume that signing a release at the counter settles the notice question — take advice on what you are signing before you sign it.
Check the dates on your own papers first
Four dates decide this, and they are usually all on documents you already hold. Note the date printed on the notice, the date you actually received it, the effective date of separation, and — if you can obtain it — the date the employer filed its notice with the department. Keep the envelope, the acknowledgment page or the message transmitting the notice, because a document dated a month back but delivered a fortnight late is a common pattern. Bring those, your payslips and the computation you were given when you consult a lawyer.