I'm not sure where Swarm is incorporated. But I know their headquarters is in Palo Alto, California.

https://www.linkedin.com/company/5229919/

Here is what the Whitepaper says:

"To actualize these aims, Swarm has established the following legal
entities:

Quantum Holonic Swarm Systems (USA)
Swarm Operations (Germany GMBH)
Swarm IP (Singapore)
Swarm Research Foundation (Panama)
Ethereum Alpha Fund (Cayman)
Bitadel Master Fund (Cayman)
Swarm Asset SPVs (Estonia, etc.)

Most of these are newly operational with the exception of Quantum
Holonic Swarm Systems which has independently been conducting
research and events from its Palo Alto office, including partnerships
with Institute for the Future, Microsoft, Intel, Ikea, H&M, Walmart, EO
Works, The Rulebreaker Society, and others. "