ISIS, the joint mobile payment venture that is backed by AT&T (T), Verizon (VZ) and T-Mobile, was previously set to debut in select markets at the end of September. Various delays have once again pushed the release date back, however, and the company confirmed as much to CNET. Ryan Hughes, head of marketing for ISIS, declined to disclose what caused the delay, saying only that the project was going through a “punch list” of objectives and it wouldn’t be too long. “Our focus has been on making sure when we launch we do it properly and do it right,” the executive said, adding that he will reveal additional “market momentum news” in October. Apple’s (AAPL) iPhone 5, which was announced yesterday, lacks an NFC chip, however Huges doesn’t see it as a setback because of the wide variety of smartphones available with the technology. He also disclosed that the group is working on a case that will add NFC capabilities to the iPhone.