Abstract: A Standard Size Convertible Transaction Card Assembly includes a conventional transaction card of standard size and a keychain size transaction card of reduced “key-tag” size which is formed from a delineated portion of the standard size transaction card and separable there-from, wherein the keychain size transaction card contains all readable transaction information required to consummate the intended transaction. The delineation may be a printed line, demarcation, a line-of-weakness or perforation, such that the keychain size transaction card can be separated from the standard size transaction card manually, or with the assist of tools. The consumer can use the Standard Size Convertible Transaction Card Assembly as a conventional, standard size transaction card or separate the keychain size transaction card at the delineation for use as an independent keychain size transaction card.