The development of information technology encourages government institutions to implement digital systems in financial administration. At the Industrial Laboratory Unit (UPT) of Tegal Regency, the recording of retribution payments is still carried out manually using Microsoft Excel and Word, making it prone to errors and inefficient. This study aims to design and implement a web-based retribution payment application to support faster and more accurate administrative management. The research employed a Research and Development (R&D) approach, with data collection techniques including observation, interviews, and literature study. The system was developed using the waterfall model, utilizing PHP, MySQL, and Bootstrap technologies, and was initially run locally through XAMPP. The implementation results show that the application is capable of managing customer data, recording transactions, generating invoices and Payment Receipts (STS), as well as producing reports automatically. Testing with the black-box method indicated that all features functioned properly. The application has proven to increase the treasurer’s efficiency, reduce recording errors, and accelerate data retrieval and reporting processes. Therefore, this application provides a practical solution to support the digitalization of retribution payment administration at the Industrial Laboratory Unit of Tegal Regency.