To sign in to Showmax, go to the Showmax website (showmax.com) and click on the "Sign In" button. Enter your registered email address or mobile number along with your password to log in to your account. If there are any issues signing in, verify that you have completed the signup process including email verification, ensure you are using the correct credentials, and check that your device is supported. If you forgot your password, you can reset it from the sign-in page. Once signed in, you can start streaming or managing your subscription and payment details easily from your account dashboard.