Flying Delta or United With a Service Dog (2026 Rules)

If you travel with a service dog — or you used to fly with an emotional support animal — the rules changed in 2021, and a lot of what's still floating around online is out of date. Here's the accurate 2026 picture for Delta and United, plus what it means if your animal is an emotional support animal rather than a trained service dog.

The rule that governs all of this (since Jan 11, 2021)

Air travel with assistance animals is set by a U.S. Department of Transportation rule that took effect January 11, 2021 and still applies today. Two things define it:

• A "service animal" for air travel is a dog — of any breed — that is individually trained to do work or perform tasks for a person with a disability (including psychiatric disabilities). Only dogs qualify.
• Emotional support animals are no longer treated as service animals. Airlines may — and all U.S. airlines now do — treat an ESA as a pet. An ESA letter carries no air-travel benefit and does not waive a pet fee.

That's the whole framework. Everything below follows from it.

Flying with a trained service dog

A task-trained service dog flies in the cabin, free of charge, on both Delta and United. What you need:

• The DOT Service Animal Air Transportation Form — a single federal form that attests to your dog's training, health/vaccinations, and behavior. The same form works for every U.S. airline.
• For a flight of 8 hours or longer, you also complete the DOT Service Animal Relief Attestation Form.
• Submit ~48 hours before departure when you book ahead (if you book inside 48 hours, you can present the forms at the gate).
• Up to two service dogs per passenger, each with its own forms. The dog must be at least four months old, current on vaccinations, under control (leashed or harnessed), and fit within your foot space without blocking the aisle.

Delta: submit the form through My Trips (Accessibility Service Request) in advance; no fee for the dog or its gear. United: upload the DOT form via My Trips / the United app ~48 hours out; trained service dogs (including psychiatric service dogs) fly free.

Airline processes and phone numbers change — confirm the current steps on Delta's service-animal page and United's accessibility page before you travel.

If your animal is an emotional support animal

Since 2021, your ESA flies as a pet. In practice that means:

• An airline-approved soft carrier (roughly 18" × 11" × 11") that fits fully under the seat in front of you, with your animal staying in it for the flight.
• The airline's in-cabin pet fee, each way. As of 2026 that's about $150 on Delta (the domestic fee rose to $150 for tickets issued on/after April 8, 2025), around $150 on United, roughly $150 on American, and about $125 on Southwest — but check your airline's current pet page, since fees move.
• Pets are not permitted in premium cabins on some aircraft (e.g., Delta One/Delta Business/Premium Select; United Polaris/Business on certain widebodies), and animals too large for a carrier generally can't travel in the cabin.

So the honest version: if air travel is the reason you're looking into documentation, an ESA letter won't get your animal into the cabin — that door closed in 2021. The only path to free in-cabin access for a disability is a dog that is task-trained for your condition — a psychiatric service dog. Otherwise your animal travels, and is charged, as a pet.

A few practical notes

• International trips add their own layer — destination countries can require pet passports, import paperwork, or quarantine (and the CDC sets rules for animals entering the U.S.). Check the specific country's requirements well before you book.
• Every U.S. airport is required to have an animal relief area past security; give your dog time before boarding.
• Airlines can refuse an animal that is out of control, aggressive, or ill — service dog or not.

Bottom line

For a trained service dog, flying is straightforward and free: the DOT form, 48 hours' notice, good behavior. For an emotional support animal, air travel now works like any other pet — carrier and fee. If you rely on your animal in the air and it's task-trained for a disability, a psychiatric service dog is the route that keeps cabin access; if comfort in daily life and housing is your goal, that's exactly what an ESA letter is for.