E-Procurement platforms transform the way organizations manage their purchasing, sourcing, and supplier interactions. As sensitive financial and supplier data flow through these systems, security is paramount. Simultaneously, ensuring seamless access for various stakeholders - internal employees, diverse suppliers, and potential partners - is essential for efficiency. Enterprise SSO and standard authentication provide a balanced solution to address these requirements. This article dives into how E-Procurement SaaS vendors can leverage the combined power of SSO and standard login, examining use cases, real-world examples, and key implementation considerations.