There is a significant challenge in the smart cities implementation because it is not straightforward to align the smart city strategy with the impact on the life of quality. Stakeholders’ concerns are multiple and diverse, and there are a high interdependency and heterogeneity of technologies and solutions. To tackle this challenge, cities can be understood as enterprises. Enterprise Architecture (EA) approach can be applied to support its development and transformation. This approach specifies core requirements on business, information, and technology domains, which are essential to model architecture components and to establish relations between these domains. Existing smart cities frame-works describe different components and domains. However, the main domain requirements and the relations between them are still missing. This paper identifies essential requirements of enterprise architecture in smart cities. These requirements will be used to review and compare current smart city frameworks.