1. Go to the right sign-in page. Use qbo.intuit.com, or click Sign In from quickbooks.intuit.com. Don't confuse this with QuickBooks Desktop or QuickBooks Self-Employed; both are separate products with their own sign-in flow, even though they share the QuickBooks name.
2. Enter your Intuit account email or user ID. It's the same account used for TurboTax or Mint if you happen to have one, not a QuickBooks-only username. Whoever set up the company originally usually knows which email that is, even if it's not the one you'd guess.
3. Enter your password and select Sign In.
4. Pick the right company if you manage more than one. After signing in, if your Intuit account has access to more than one QuickBooks company, your own business, a client's, a nonprofit you volunteer for, you'll land on a list instead of a single file. Select the correct one before touching anything.
5. Confirm a verification code if Intuit asks for one. A text or email code shows up occasionally, especially from a new device or browser. That's a normal security check, not a sign anything's wrong with the account.