Every new Connecticut business filing, every dayKatherine Sullivan
Katherine Sullivan, Principal
Katherine Sullivan LLC appears to be the professional entity for Katherine Sullivan, a licensed clinical social worker (LCSW) based in Westport, CT. The Healthgrades profile lists her practice address at 215 Main St, Westport, CT, and indicates she is accepting new patients. The filing's principal address is 181 Post Road West, Westport, CT, suggesting a possible office location or registered address.
Filed March 3, 2026 · Westport, CT · Fairfield County
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Connecticut Secretary of the State (business.ct.gov) · Entity 3389871 · Retrieved July 26, 2026
About Katherine Sullivan
Katherine Sullivan LLC filed in Connecticut on March 3, 2026, and was first seen 145 days later. Principal Katherine Sullivan is the owner. The domain was registered 9,843 days before filing, in 1999, through GoDaddy Corporate Domains, and the website is modern and confirmed to match the filing's name and address. The business is a social work and mental health practice based in Westport. We estimate revenue under $100,000 with 1 to 5 employees. No annual report or EIN on file yet.
- Domain registered 9,843 days before filing, in 1999.
- Website confirmed to match the filing's name and address.
- Website is modern.
- We estimate revenue under $100,000 and 1 to 5 employees.
- No annual report or EIN on file yet.
Compiled from the state record, the company's public web presence, and our own research; revenue, employee, and footprint figures are estimates, not verified financials. Updated August 24, 2026.
One of 67 new businesses registered in Westport in March 2026, and the only healthcare business registered there that month.
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Filing Details
Verified Business Profile
Contact Information
Verified Website Profile
We matched this business to its website and pulled the domain's registration (WHOIS) record. Domain age is one of the strongest signals that a filing is a truly new business and not a re-filing or paperwork change.
Officers / Authorized Persons
Frequently Asked Questions
When was Katherine Sullivan registered?
Katherine Sullivan was registered as LLC on March 3, 2026 in Connecticut.
Where is Katherine Sullivan located?
Katherine Sullivan is based in Westport, CT, 06880, in Fairfield County.
What type of business is Katherine Sullivan?
Katherine Sullivan is classified as a healthcare business (social work / mental health).
Does Katherine Sullivan have an EIN on file?
No EIN was found on file for Katherine Sullivan at the time of registration.
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