A Data Processing Agreement (DPA) is a GDPR-required contract that governs the handling of personal data between a controller (the organization deciding why and how data is processed) and a processor (a vendor processing data on the controller’s behalf). For customer portals serving EU residents, signing a DPA with every vendor in the data chain is a GDPR compliance prerequisite.
A DPA typically specifies: the categories of personal data processed, the purposes of processing, security measures, sub-processor disclosures, breach notification timelines, and the data return/deletion procedure when the contract ends. Most reputable SaaS portal vendors have a standard DPA they’ll sign on request.