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.io Domain: British Indian Ocean Territory ccTLD Guide

Updated October 2026

.io is the country-code top-level domain for the British Indian Ocean Territory. The startup and developer favourite.

Overview

Read as "input/output", .io became a default for software companies, developer tools and tech startups.

.io is the country code for the British Indian Ocean Territory (the Chagos Islands). Its popularity has nothing to do with geography: in computing, I/O means input/output, so the ending reads naturally for technical products.

In October 2024 the UK announced it would hand sovereignty of the Chagos Islands to Mauritius, and a treaty was signed in May 2025. Because ccTLDs follow ISO country codes, that raised questions about .io's long-term future. In April 2026 the UK paused the legislation needed to complete the handover, because the United States had not given its formal consent. If the IO code were ever removed from the ISO list, IANA practice is to retire a domain over a transition period, typically around five years, though exceptions such as .su exist. Nothing has been decided, but owners of important .io names should follow the news.

Prices for .io are usually higher than for .com, and renewals can be a meaningful yearly cost if you hold many names.

Who can register

Generally open to registrants worldwide through many registrars.

Before you buy a .io name

• Check the renewal price as well as the first-year price. Our cost calculator shows what a name really costs over time.
• Make sure you meet the eligibility rules yourself, without relying on a trustee if you can avoid it.
• Search for trademarks and for the same name in .com.
• Say the name out loud: will people type it correctly?

Weighing up a specific .io name? TLD.is gives an AI appraisal that explains a name's strengths and weaknesses.

Frequently asked questions

What country is .io?

.io is the country-code top-level domain for the British Indian Ocean Territory.

Who runs the .io domain?

The .io registry is managed by Internet Computer Bureau (ICB).

Can I register a .io domain from another country?

Generally open to registrants worldwide through many registrars.

Does Google treat .io as a country domain?

Google treats .io as a generic ending, like .com, rather than as a signal for the British Indian Ocean Territory.

Compare and explore

Compare .io side by side with other extensions, or browse more in Africa:

Sources checked: en.wikipedia.org. Last reviewed October 2026.

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