COA can refer to: Cambridge Occupational Analysts Cash on Arrival Cause of action CedarOpenAccounts COA (formerly CedarOpenAccounts) Center of Attention Certificate of Approval for marriage or civil partnership in the United Kingdom Certified Ophthalmic Assistant Change of Address forms used by the United States Postal Service Ciphertext-only attack model Clowns of America International (COAI), formerly Clowns of America (COA) Coat of Arms Collaboration Oriented Architecture College… (More on Coa)