AbstractElectronic tax documents represent an important advance in the process of digital transformation of tax administrations in Brazil. However, the current system still presents several challenges to be overcome. In the technological aspect, vulnerabilities and inconsistencies typical of a centralized model can be mentioned. In addition, from a functional perspective, the lack of control over taxes payments is a major concern. In this context, Blockchain technology emerges as a possibility to complement the current model, thanks to its characteristics, such as traceability, immutability, security and transparency, which are essential in the tax environment. This work proposes four application models based on Blockchain aimed at monitoring the payment of taxes, using different types of integration with existing systems. After the presentation and description of the models, they are discussed and compared, in order to reinforce their main characteristics, facilitating decision making in possible future applications.