Join'ss Laundry still records orders, monitors laundry status, and prepares transaction reports manually using a record book. This condition causes slow data retrieval, requires customers to call or visit in person to check their laundry status because the receipt only contains an estimated time, and poses a risk of recording errors and data loss. This research aims to design and develop a website-based laundry service information system to improve the efficiency of order recording, laundry status monitoring, and transaction reporting at Join'ss Laundry. The system was developed using the Waterfall method, which includes the stages of communication, planning, modeling, construction, and deployment. Data were collected through observation, interviews, and literature study. The system was built using the PHP programming language and MySQL database with the XAMPP local server. System analysis and modeling were carried out using Flowchart, Data Flow Diagram (DFD), and Entity Relationship Diagram (ERD), while testing used the Black Box Testing method. The result is a website-based laundry information system with two access roles, namely admin and customer. The system provides online ordering and cashier transactions, pickup and delivery service with on-site weighing at the customer's location, automatic cost calculation and queue numbers, real-time laundry status monitoring, digital receipts via WhatsApp, and transaction reports. Black Box Testing shows that all main features function as required. Thus, the system serves as a digital solution to the manual recording problem at Join'ss Laundry.