If you deactivate your account, all your information still exists on Ashley Madison, so it is still at risk to be leaked or hacked.

You’ll be redirected to an account deactivation page where you will need to give a reason for your deactivation. Choose one and click “Deactivate” and confirm your action in the pop-up.

Confirm the deletion in the pop-up. The full deletion of your account may take up to 48 hours to complete. [1] X Research source