The focus on preventing medical errors has advanced the arguments for widespread implementation of electronic prescribing. The choice of systems as well as the variation in functionality is large. Value and return on investment depend on the functionality provided. The paper by Douglas Bell and colleagues defines the functionalities that are required and desirable to ensure patient safety and quality of care. Health data standards are a prerequisite for the interoperability to support electronic prescribing. This paper discusses some of the barriers and problems in producing and adopting those standards.