You’ll see this on your paper bill—a string of numbers, usually 10 to 16 digits long. Do not lose this. It’s basically your water bill’s social security number. Fun fact: Without it, you’re just a thirsty person yelling at a screen.
Also, have your billing address and ZIP code handy. Some websites ask for that as a security check. It’s like the bouncer at a club, but way less intimidating.