- "Firm" or "law firm" denotes a lawyer or lawyers in a law partnership, professional corporation, sole proprietorship or other association authorized to practice law; or lawyers employed in a legal services organization or the legal department of a corporation or other organization.
What constitutes a firm depends on the specific facts. It can exist if they present themselves in a way that suggests that or if they conduct like a firm.
A firm can have several offices in different cities, and they will all be one firm.
A firm can exist for some purposes, like prohibiting representing both sides, but not for other purposes, like attribution of knowledge.