This document summarizes the Plan4all project, which aims to harmonize spatial planning data across Europe according to the INSPIRE Directive. The project will develop a metadata profile, data models, and networking architecture to facilitate sharing of land use, land cover, and other spatial planning data themes. A geoportal will be established to allow access to harmonized spatial planning data from local and regional partners. The overall goal is to support seamless access to spatial planning information across borders through interoperable data standards and services.