# Combined sign-in-or-up

The `<SignIn />` component now allows users to sign up if they don't already have an existing account. When attempting a sign-in and no existing account is found, users will be prompted to continue through the flow to create an account, without needing to navigate to a separate route where `<SignUp />` is mounted.

The combined flow is a great option when email-based authentication strategies are used, as the sign-in and sign-up flows tend to be very similar.

To start using the combined sign-in-or-up flow, remove your existing `<SignUp />` usage, and unset `CLERK_SIGN_UP_URL`. Your existing `<SignIn />` component will now handle sign ups.

While this is the new default behavior, you can opt out of the combined flow by defining your `CLERK_SIGN_UP_URL`.

For more information, including how to build a dedicated `<SignUp />` page, visit the [documentation](https://clerk.com/docs/references/nextjs/custom-sign-up-page.md).