The ESA letter has become the centerpiece of housing accommodation disputes. Landlords scrutinize them. Tenants scramble to get them. Online services sell them. Courts sort out what's legitimate. Here's where things stand in 2025.
Federal vs. State Requirements
There is no federal regulation prescribing a specific format for ESA letters. HUD guidance describes what information should be conveyed but doesn't mandate a specific format. California's AB 468 went further — requiring a patient relationship of at least 30 days. Other states may follow.
What a Valid ESA Letter Should Include (2025)
- Healthcare provider's name, license type, license number, and state of licensure
- Provider's contact information and signature
- Date of the letter
- Statement that tenant has a disability under FHA (without naming the diagnosis)
- Statement of disability-related need for an emotional support animal
- Confirmation of an ongoing therapeutic relationship
What a Valid Letter Does NOT Need
- Your specific diagnosis
- Treatment history or medication information
- Any ESA "registration" number
- Proof of the animal's training
Online ESA Services: Caution
A legitimate telehealth service that conducts real assessments with licensed providers can provide valid documentation. Instant-letter services with no real clinical relationship are legally weak and increasingly challenged. Invest in getting a letter from someone who actually knows you.
Annual Renewal
No federally mandated expiration date. Landlords may request updates at annual lease renewal — courts find annual requests reasonable, more frequent demands are not.