ART.169. How Forgery is Committed

a. by giving to a treasury or bank note or any instrument payable to bearer or to order, the appearance of a true and genuine document;
b. by erasing, substituting, counterfeiting, altering by any means the figures, letters or words, or signs contained therein.

If all acts are done but genuine appearance is not given, the crime is frustrated.

P.D. No. 247 punishes the willful defacement, mutilation, tearing, burning, or destruction in any manner of currency notes or coins issued by the Central Bank of the Philippines.

For possession of false treasury or bank note to constitute a criminal offense, it must be with intent to use.

The essence of forgery is giving a document the appearance of a true and genuine document. Not any alteration of a letter, number, figure or design would amount to forgery. At most, it would only be frustrated forgery.

People vs. Galano, 3 SCRA 650
It was held that forgery can be committed through the use of genuine paper bills that have been withdrawn from circulation, by giving them the appearance of some other true and genuine document.
However, the dissenting opinion stated that the provision only embraces situations in which spurious, false or fake documents are given the appearance of a true and genuine document.