Glossary
SSO (single sign-on)
Also called: Single sign-on
In one sentence
Signing in once with one strong company account to reach many different apps, instead of a separate password for each.
With single sign-on, staff use their Microsoft 365 work account — protected by MFA — to sign in to other business apps: your practice software portal, payroll, a CRM, a file-sharing tool. The app trusts Microsoft Entra ID to confirm who the user is, instead of keeping its own password.
SSO helps security and convenience at the same time. Staff have fewer passwords to remember, so they’re less likely to reuse weak ones. MFA and Conditional Access rules apply to every connected app in one place. Most importantly, when someone leaves, disabling one account cuts off access to everything connected to it.
Not every app supports SSO, and some vendors only offer it on more expensive plans. For apps that don’t, a business password manager is the next best thing. It’s worth asking vendors about SSO support (often called SAML or OpenID Connect) before you buy, and listing which of your apps already support it so new accounts are created the right way from the start.
Example: a growing startup connects its code repository, HR system and project tool to Entra ID. When a developer leaves, the IT provider disables one account and access to every system ends at once — the kind of identity control described in our software startup case study. See also Microsoft 365 & identity.
Related terms
- Microsoft Entra IDMicrosoft Entra ID (formerly Azure Active Directory) is Microsoft's cloud identity service — the system that holds your users' accounts and controls how they sign in to Microsoft 365 and other apps.
- MFA (multi-factor authentication)MFA means signing in with something you know (a password) plus something you have or are (a phone app, security key or fingerprint), so a stolen password alone isn't enough.
- Conditional AccessConditional Access is the Microsoft Entra ID feature that decides, at every sign-in, whether to allow, block or require extra checks based on who is signing in, from what device, and from where.
- Password managerAn encrypted app that creates, stores and fills in strong, unique passwords, so staff don’t have to remember or reuse them.
- Zero trustZero trust is a security approach that never assumes a user or device is safe just because it's inside the office network — every access request is verified based on identity, device health and context.