How Dynamics 365 apps connect

One of the most important things to understand about Dynamics 365 is that it isn't really one application — it's a portfolio of apps wired together by a shared platform. Knowing which connections are tight and which are loose is the difference between an architecture that scales and one that fights you forever.

Identity is the tightest connection. Every Dynamics 365 app authenticates against Microsoft Entra ID (formerly Azure AD), so users get single sign-on across CRM, Business Central, Finance, and the Power Platform — including from Outlook, Teams, and SharePoint.

Data is the next layer. The CRM-side apps (Sales, Customer Service, Field Service, Project Operations, Customer Insights) all run natively on Microsoft Dataverse, so they share the same Account, Contact, and User tables out of the box. Cross-app reporting and security work without ETL. The ERP-side apps — Finance, Supply Chain Management, and Business Central — have their own first-party databases, and integrate with Dataverse through virtual tables or replicated data. This means a Customer record in Sales is not automatically the same record as a Customer in Business Central; you need an integration to keep them aligned. Microsoft ships pre-built ones (Dataverse virtual tables for BC; the Dual-write framework for Finance and SCM), but they still need to be configured and monitored.

Workflow and analytics are loose connections, delivered by the Power Platform. Power Automate flows can trigger across any combination of apps; Power BI can build dashboards over multiple Dataverse environments and the BC/F&O data lakes; Copilot Studio agents can read and write to any of them.

Files are stored in SharePoint and OneDrive, which every Dynamics 365 app integrates with for document management.

The practical upshot is that mixing a CRM app with a separate ERP is normal, and the integration cost between them is the price of the platform's modularity. Plan for it from day one.