Dishonored checks as proofs of pre-existing obligation or as guarantee for the performance of a future obligation.

See - http://sc.judiciary.gov.ph/jurisprudence/2012/june2012/185522.htm#_ftnref27

"x x x.

We find, however, that aside from its bare assertions on appeal, SMC failed to present any evidence to prove that cash transactions were treated differently from check transactions. Respondent correctly argues that if the check transactions were covered by other statements of account, petitioner should have presented evidence of those transactions during the proceedings before the lower court.[33]

In any event, we cannot allow SMC to recover the amount of ₱921,215 from respondent, as it failed to prove the existence of the purported indebtedness. The records are bereft of any evidence, other than the dishonored checks, establishing the existence of that obligation. Checks, however, are not issued merely for the payment of a preexisting obligation. They may likewise be issued as a guarantee for the performance of a future obligation. In this case, it was sufficiently established that the dishonored checks were issued merely to guarantee the performance of a future obligation; that is, the payment of the net value of the goods after the value of the empty bottles and beer cases returned to petitioner were deducted from the gross value of the goods delivered to respondent.

x x x."