Sign in once: what single sign-on means

What it is

With single sign-on, one trusted account, usually your Microsoft 365 work account, proves who you are to other apps: accounting, payroll, scheduling, customer records and so on. You sign in once, and the other apps accept it.

Why it helps

• Fewer passwords to create, remember and leak.
• Multi-factor authentication everywhere, because the apps rely on your protected work sign-in.
• One switch for departures. When someone leaves, turning off their work account turns off every app connected to it.
• A record of who signed in to what, in one place.

What to watch

• The work account becomes the key to everything, so it needs strong multi-factor authentication.
• Not every app supports it, and some charge more for it.
• Review which apps are connected. Staff can sometimes approve new apps themselves, giving them access to their mailbox or files.

A good place to start

List the apps your business uses and check which offer “Sign in with Microsoft.” Moving the important ones over is usually quick, and it makes the next departure much simpler.