Visas and Officialdom
No passports or visas are required for U.S. citizens entering Puerto Rico. Those visiting the island from other countries must have the same documentation required to enter the United States. Visitors from the United Kingdom are required to have a British passport but do not need a visa unless their passports are endorsed with British Subject, British Dependent Territories Citizen, British Protected Person, British Overseas Citizen, or British National (Overseas) Citizen. A return ticket or proof of onward travel is necessary. Australian visitors must have a passport and can stay up to 90 days without a visa.
© Suzanne Van Atten from Moon Puerto Rico, 2nd Edition