British Indian Ocean Territory
Phone Code
+246
Capital
Diego Garcia (military base)
Population
3,000 (2018)
Languages
Area
60 km²
Driving side
right
Native Name
British Indian Ocean Territory
Region
Africa
Eastern Africa
Timezone
Indian Ocean Time
UTC+06:00
On This Page
The British Indian Ocean Territory (BIOT) comprises the Chagos Archipelago, a group of 58 islands and atolls scattered across 54,400 square kilometres of the Indian Ocean, approximately 500 kilometres south of the Maldives. The largest and only inhabited island, Diego Garcia, hosts a joint UK-US military facility that serves as a strategic naval support base. BIOT is administered from London as a British Overseas Territory through the BIOT Administration, with day-to-day access governed by a strict permit system rather than an open border. For travellers, this means BIOT is entirely off-limits under ordinary circumstances: civilian access requires specific written authorisation, no tourism infrastructure exists, and vessels entering territorial waters without permission are turned away or intercepted.
Access Restrictions for British Indian Ocean Territory
The British Indian Ocean Territory operates on a permit-only access model. UK law requires any person not authorised by the BIOT Administration to hold explicit written permission before entering the territory, and that permission is granted almost exclusively for official government business or approved scientific research. The Diego Garcia military facility operates under a UK-US agreement restricting access to military personnel, defence contractors and specifically authorised government officials — even UK and US citizens need military orders or official authorisation to visit. The permit system extends to territorial waters: private yachts, cruise ships and recreational vessels may not approach within 3 nautical miles of any island without clearance, and the UK military actively patrols the exclusion zone. No commercial flights serve the territory; the only airstrip, on Diego Garcia, is reserved for military aircraft. For any civilian traveller, BIOT functions as a closed, permit-based territory rather than a conventional destination.
Common Visa Types
Permit-Based Access Only
Civilian entry — including tourism, general research, and private vessel visits — requires specific written permission from the BIOT Administration, granted almost exclusively for official government business or approved scientific research under strict supervision.
Essential British Indian Ocean Territory Information
•Civilian access requires specific written...
•Diego Garcia hosts a major...
•Private vessels may not enter...
•No commercial flights exist. The...
•The Marine Protected Area designation,...
•The underwater environment includes pristine...
•The UK leases Diego Garcia...
•The territory's ".io" internet domain...
•For travellers, BIOT is a...
The British Indian Ocean Territory is not open to casual civilian visits. The Chagos Archipelago features pristine coral reefs, abundant marine life, and tropical vegetation on low-lying atolls, but these natural assets sit within a permit-controlled military exclusion zone. Diego Garcia island houses extensive military infrastructure — a naval port, airfield, fuel storage, communications facilities and accommodation for around 3,000 UK and US military personnel and contractors. The surrounding waters hold exceptional marine biodiversity: healthy coral systems, large pelagic fish, sharks, rays, dolphins and nesting sea turtles. The outer atolls remain largely undeveloped, covered in coconut palms and scrub vegetation around turquoise lagoons. The UK designated the territory a Marine Protected Area in 2010, creating one of the world's largest no-take marine reserves and giving these waters some of the strictest environmental protection found anywhere in the Indian Ocean. The territory's ".io" internet domain, unrelated to any of this, has separately become widely used by technology companies worldwide.
Discover British Indian Ocean Territory
A closed military zone, not a travel destination
The British Indian Ocean Territory is administered as a closed military area rather than a travel destination: UK law bars any person without specific written authorisation from entering, and the only airstrip, on Diego Garcia, handles military aircraft exclusively — there is no commercial air or sea access of any kind. Diego Garcia itself hosts a joint UK-US naval and airfield facility supporting around 3,000 military personnel and defence contractors, all of whom enter under military orders or specific security clearance rather than any form of civilian visa.
One of the world's largest marine protected areas
Beyond the base itself, the surrounding waters were designated a Marine Protected Area in 2010, creating one of the largest no-take marine reserves on Earth and shielding coral reefs, large pelagic fish, sharks, rays, dolphins and nesting sea turtles from commercial fishing and development. The outer atolls of the Chagos Archipelago remain largely undeveloped — coconut palms and scrub vegetation ringing turquoise lagoons — but sit inside a 3-nautical-mile exclusion zone that applies to all private vessels, enforced by active UK military patrols.
Ways to Experience This Destination
Civilian travel to BIOT requires prior written authorisation from the BIOT Administration. Outside a small number of government-approved scientific research missions, the territory has no tourism infrastructure and no general visitor access. Private vessels approaching without clearance are turned away by patrolling UK military craft, and the marine protected area's research provisions are administered directly by UK authorities on a case-by-case basis. In practice, the people who set foot on BIOT are military personnel, defence contractors with security clearances, and government officials on official business.
For most people, engagement with the British Indian Ocean Territory happens remotely. Satellite imagery shows the military installations on Diego Garcia alongside the pristine outer atolls, and environmental scientists study the territory's marine ecosystems through satellite data and the occasional authorised research mission, since the Marine Protected Area status keeps much of the underwater environment largely undisturbed by human activity. The ".io" domain suffix, unrelated to the territory's geography, has separately become a recognisable piece of global internet infrastructure.
Money & Currency
US Dollar (USD)
Currency code: USD
Practical Money Tips
US Dollar Is the Only Currency — Diego Garcia Is a Restricted Military Base
The British Indian Ocean Territory (BIOT) consists of the Chagos Archipelago in the central Indian Ocean. The main island, Diego Garcia, hosts a joint UK–US military facility. The US dollar (USD) is the currency used on Diego Garcia for all on-base transactions. The territory is not open to civilian tourism — access is restricted exclusively to authorized military personnel and essential contractors. Civilian visitors are not permitted.
Banking Available Only for Military Personnel on Diego Garcia
Diego Garcia has on-base banking facilities for authorized military personnel and Department of Defense contractors. These are not accessible to civilian visitors. The outer islands of the Chagos Archipelago have no population, no infrastructure, and no financial services. Some research and yacht-passage permits have historically been granted, but services remain extremely limited.
Cards and Digital Payments on Diego Garcia — Military Facilities Only
Card payments and US military digital payment systems operate within the Diego Garcia base for authorized personnel. Apple Pay, Google Pay, and civilian banking cards cannot be used by the general public, as access is not permitted. Scientists and contractors may have access to base facilities subject to authorization.
Expedition and Research Budgets — All in USD Pre-Departure
For the rare authorized research expedition to the Chagos Archipelago's outer islands, all expenses must be financed in USD before departure. There are no shops, services, or infrastructure on the outer atolls. Expeditions must be entirely self-sufficient. All permits are obtained through the BIOT Administration (London) or the US Navy command.
Note: Always check current exchange rates before traveling. Currency exchange is available at airports, banks, and authorized money changers.
What currency is used in the British Indian Ocean Territory?
Can tourists visit the British Indian Ocean Territory?
Can I use Apple Pay, Google Pay, or cards in BIOT?
What is the British Indian Ocean Territory?
Is there any civilian population in BIOT?
What currency would I need for an authorized research permit to Chagos?
What is the status of BIOT and Diego Garcia?
Is there anything to buy in the British Indian Ocean Territory?
Can I visit the British Indian Ocean Territory?
No. Civilian access is prohibited under UK law without specific written authorisation, which is granted only in exceptional cases for official government business or approved scientific research.
Why is Diego Garcia off-limits?
Diego Garcia hosts a joint UK-US military naval and airfield facility, and access is restricted to military personnel, defence contractors and specifically authorised government officials — there's no commercial flight or ferry service of any kind.
Can I sail a private yacht through the territory's waters?
No — private vessels are prohibited from entering within 3 nautical miles of any island in the territory, and the exclusion zone is actively patrolled and enforced.
Is the territory a marine reserve?
Yes — the surrounding waters were designated a Marine Protected Area in 2010, one of the largest no-take marine reserves in the world, protecting coral reefs, sharks, rays, dolphins and nesting sea turtles from commercial fishing.
Who administers the British Indian Ocean Territory?
The United Kingdom, which governs it as a British Overseas Territory through the BIOT Administration, with Diego Garcia operated jointly with the United States under a long-term defence agreement.
Are there commercial flights to the territory?
No — the only airstrip, on Diego Garcia, is used exclusively for military aircraft, and there is no scheduled commercial air or sea transport to any island in the territory.
What wildlife lives in the territory's waters?
The reefs support large pelagic fish, sharks, rays and dolphins, and the outer atolls provide nesting sites for sea turtles, all largely undisturbed by human activity given the restricted access.
Why does the ".io" domain relate to this territory?
".io" is the internet country-code domain assigned to the British Indian Ocean Territory, and it became widely used by technology companies for reasons unrelated to the territory itself.
Visaja keeps this page's contact details and visa guidance under continuous review — still, requirements can change at short notice, so confirm the essentials with the mission or the official government portal before you travel.