Confusion abounds when it comes to emotional support animals (ESAs).I’ve read stories about dogs pooping on planes, reporters parading llamas and turtles into shops around town, and the implied problem of the fakers — those who don’t really need an ESA, but who exploit the law to get around airline fees.

As someone who really does need her ESA, I find this all pretty distressing. My own dog, Luna, quite literally got me off antidepressants, and I know others whose dogs have reduced or even eliminated panic attacks and debilitating anxiety. Even more distressing than the confusion, though, is the fact that for people who need an ESA, the Internet is clogged with useless and incorrect information.

Let me try to set that right by answering the three main questions about these valuable companions.

1. What is an emotional support animal (ESA)?

An emotional support animal is a dog (or cat) who accompanies a person with an invisible (emotional or mental) disability. And under the law they are protected in two main ways:

1. ESAs are allowed in no-pet housing, and the landlord cannot charge an additional fee.
2. ESAs are allowed to fly in-cabin and outside a carrier on any U.S. flight (both flights within the U.S. and flights to and from the U.S. from abroad).

That’s it.

Those are the protections. As a disabled person with an ESA, you can’t legally be denied housing or flights.Which means that ESAs are not legally guaranteed entry into other no-dog spaces such as restaurants, no-pets hotels, and other no-pets businesses. If you do need your dog in one of those spaces, you’ll have to ask the owner, and they are fully within their rights to say no.

That said, I find most owners are compassionate when it comes down to it. When I missed a flight and got stranded in New York City overnight, a no-pets hotel made an exception and allowed Luna and I to book a room. When I was training Luna for therapy work — to work in hospitals with kids — I asked nicely if we could dine on some outdoor patios that normally didn’t allow dogs. About half of the time, the owners said yes.

Keep in mind, though, that business owners do not have to accommodate an ESA. If you have such an animal, make it clear that you are asking for permission to enter a no-pets zone. Make sure they know you aren’t trying to bully them, going to sue them, etc. That you just need a room for the night at the last moment and don’t have time to search for a pet-friendly option. Or you just want to grab lunch and happen to have your ESA with you. And whatever the owner says, thank them for their consideration and respect their decision.

2. What are the legal requirements to get an ESA?

In order to have your dog (or cat) legally qualified as an ESA, you’ll need a letter from your mental health professional that states three important things:

1. That you have been diagnosed with a disability recognized in the Diagnostic and Statistical Manual of Mental Disorders, 4thEdition.
2. That you require your animal as an accommodation for air travel or an activity at your destination.
3. That you are under the ongoing care of the mental health professional who wrote the letter and that the person is licensed to diagnose mental health disabilities.

The letter must also be on the letterhead of your mental health professional and have the full contact information and license information (date, type, issuing state) for said mental health professional (the airlines and your landlord are within their rights to call and confirm its authenticity, though they may not ask about your specific disability). The letter is good for one year (then your mental health professional will need to update it). I always recommend having copies of it on your computer and in several places in hard copy.

That’s it. That’s the paperwork for an ESA. Keep in mind that the letter must be from a mental health professional whose care you are under, as I said above. This means letters purchased online are probably not valid. Also note that you do not need a vest or badge for your ESA, and a vest or badge does not make an ESA valid.

3. Are there additional requirements for air travel?

Another important thing to know about ESAs is that they are still subject to the animal import and export requirements of states and countries. This means that if you are flying overseas, you will still need to fill out paperwork and comply with any quarantine laws in the country you are traveling to. So if you are taking your ESA abroad, make sure to research the country’s travel requirements long before you travel.

You should also note that even though ESAs don’t have a specific training requirement, they are expected to be well-behaved. Legally, an airline is allowed to deny you entry to the plane if your animal is behaving aggressively, defecating, or otherwise causing a scene.

Also, keep in mind that only dogs and cats are fully legally protected as ESAs. Airlines may choose not to fly other animals, even if you have a letter.

The information above is based on my experiences and my reading of legal documents, but understand: I am not a legal professional. Before you travel with or paper your own ESA, make sure to check the regulations.

For more information about the legalities of ESAs, check out this helpful resource from the Americans With Disabilities Act National Network. Here’s the number for the Department of Transportation disability hotline: 800-778-4838. And here is my always-updated Q&A on the topic.

Read more from Gigi about traveling with an ESA:

• 5 Things I Learned While Traveling the World With My Dog
• What Having an Emotional Support Dog Means to Me
• Q&A: How I Travel Internationally with a Large Dog
• Britain Denied Me Entry for Traveling with My Dog, an Emotional Support Animal
• The Beginner’s Guide to Flying Internationally with Your Dog
• The 5 Stages of Dog Jet Lag

Gigi Griffis is a world-traveling entrepreneur and writer with a special love for inspiring stories, new places, and living in the moment. In May 2012, she sold her stuff and took to the road with a growing business and a pint-sized pooch. You can follow her adventures at gigigriffis.com or friend her on Facebook.