A senior executive at mobile wallet and payment network Isis has announced the company will miss their planned summer launch date. Head of marketing Jaymee Johnson told FierceMobileContent that Isis is still fine-tuning their product and as such, it won’t be ready by September 21 – the first day of fall.

The joint venture between AT&T, T-Mobile and Verizon to create a NFC network similar to Google Wallet began in November 2010. Salt Lake City and Austin will be the first two cities to support the platform and according to Johnson, there are hundreds of merchants in those cities ready to go.

We are now being told that Isis will have further information regarding their progress sometime in October. Johnson said there wasn’t one particular problem that delayed the launch but instead, they are simply working through a handful of small issues to ensure the best possible customer experience. The executive likened it to checking items off a punch list.

Isis has signed agreements with American Express, Chase, Capitol One and Barclaycard to conduct point-of-sale transactions at a number of different merchants. HTC, LG, Motorola, Research in Motion, Samsung and Sony have all confirmed they will be releasing products to support the platform.

Johnson didn’t specify if Isis would be ready for launch in October or not. Furthermore, it’s unclear how quickly the platform plans to expand past the two launch cities. With any luck we’ll know the answers to these questions next month.