: Recently, the software industry has published several proposals for transactional processing in the Web service world. Even though most proposals support arbitrary transaction models, there exists no standardized way to describe such models. This paper describes potential impacts and use cases of utilizing advanced transaction meta-models in the Web service world and introduces a suitable meta-model for defining arbitrary advanced transaction models. In order to make this meta-model more usable in Web service environments, it had to be enhanced and an XML representation of the enhanced model had to be developed.