|Introduced||16 September 1997|
|TLD type||Country code top-level domain|
|Registry||Afilias, subsidiary of Ethos Capital|
|Intended use||Entities connected with British Indian Ocean Territory|
|Actual use||Popular with startup companies and browser games; little if anything related to the territory itself.|
|Registration restrictions||None for 2nd level registrations; 3rd level registrant must be resident of British Indian Ocean Territory|
|Structure||Registrations are taken directly at the second level or at third level beneath various 2nd-level labels|
|Documents||Terms & Conditions; Rules|
|Dispute policies||Dispute Resolution Policy|
The Internet country code top-level domain (ccTLD) .io is nominally assigned to the British Indian Ocean Territory. The domain is operated commercially by Afilias, a domain name registry subsidiary of Ethos Capital.
The .io domain was delegated by the Internet Assigned Numbers Authority to British entrepreneur Paul Kane in 1997 together with the ccTLDs .ac (Ascension Island), .sh (St Helena), and .tm (Turkmenistan). Kane operated them for private benefit under the trade name "Internet Computer Bureau" from 1997 until 2017. In 2014, Kane claimed that "profits are distributed to the authorities for them to operate services as they see fit" and that "Each of the overseas territories has an account and the funds are deposited there because obviously the territories have expenses that they incur and it’s offsetting that." However the UK government has repeatedly stated that this is untrue: “There is no agreement between the UK Government and ICB regarding the administration of the .io domain” and "the Government receives no revenues from the sales or administration of this domain."
In 2021, the United Nation's International Tribunal for the Law of the Sea ruled that the United Kingdom has no sovereignty over the Chagos Archipelago, and that sovereignty instead belongs to Mauritius. This would extinguish the British Indian Ocean Territory, and the IO ISO-3166 two-letter country code and .io domain could also be extinguished. The United Kingdom disputes and does not recognise the tribunal's decision, so further legal processes are likely.
In July 2021, the Chagos Refugees Group UK submitted a complaint to the Irish government against domain-name speculators Paul Kane and Ethos Capital subsidiary Afilias, seeking repatriation of the .IO ("Indian Ocean") country-code top-level domain and payment of back royalties from the $7m/year in revenue generated by the domain. While attempts to repatriate top-level domains are not uncommon, this one is notable in that it cites consumer and human rights violations of the OECD's 2011 Guidelines for Multinational Enterprises rather than multistakeholder representation under ICANN policy, and because the .IO domain has enjoyed commercial success, particularly among cryptocurrency companies, with more than 270,000 domains registered.
Individuals and organisations are allowed to register .io domains.
Labels for .io domains may only contain alphanumeric characters and hyphens, and must be between 3 and 63 characters long. Domain names cannot begin or end with a hyphen symbol, and may not contain two consecutive hyphens. The entire domain name may not contain more than 253 characters.
Applicants for the registration of .io domains do not need to be registered or established in the British Indian Ocean Territory. Third-level domains, such as "xyz.com.io", can only be registered by an inhabitant of the area. (Since there are no legal, permanent inhabitants of the British Indian Ocean Territory, theoretically no third-level domains will be registered.) Any second-level domains used by NIC.IO and top-level domains cannot be used as a third-level domain. For example, the domains "com.com.io", "org.com.io", and "biz.com.io" are all restricted.
Domain names in .io may not be used, "for any purpose that is sexual or pornographic or that is against the statutory laws of any nation." If this requirement is breached, "NIC.IO reserves the right to immediately deactivate the offending registration."
.io domains may be registered for a minimum of one year, and a maximum of 5 years.
Domain names in .io are priced higher than those in many other TLDs. Registering an available .io-domain currently (as of 3 September 2020) costs US$90 per year.
The .io domain is used almost exclusively for purposes unrelated to the British Indian Ocean Territory.
In computer science, "IO" or "I/O" is commonly used as an abbreviation for input/output, which makes the .io domain desirable for services that want to be associated with technology. .io domains are often used for open source projects, application programming interfaces ("APIs"), startup companies, browser games, and other online services.
The TLD is also used for domain hacks, as the letters "io" are an ending of many English terms. For example, Rub.io is a shortened URL that was used for the 2016 U.S. presidential campaign of Marco Rubio.
One reason given for the TLD's popularity is that it stands out by being shorter than other TLDs. Also, the .io TLD is less occupied than other TLDs, so it is more likely that a given term is available there.
In Italian, io is the first-person singular pronoun (English "I"), which makes the domain appealing for personal websites.
In Esperanto, io as an independent word is the assertive existential indefinite pronoun (English "something"). As a suffix, -io is used to terminate official names of countries or other kind of lands under which a community of people are grouped. The Plena Ilustrita Vortaro de Esperanto include almost 500 terms like that, from Abisenio (former name of Ethiopia, Etiopio) to Zambio (Zambia). Derived from that, the suffix is also used to designate a community of people whose common interest is indicated by the suffixed root, especially in the term Esperantio, the community of speakers of the language and their culture as a whole, as well as the places and institutions where the language is used. As of May 2020, the esperant.io domain name redirects to Libera Folio, an independent generalist online bulletin written in Esperanto.
Around 2015 a multiplayer game, Agar.io, spawned many other games with a similar playstyle and .io domain, such as Diep.io, Slither.io, Surviv.io, ZombsRoyale.io, and Hole.io. Such games are collectively called ".io games".
According to a 2014 Gigaom interview with Paul Kane, then chairman of the Internet Computer Bureau, the domain name registry is required to give some of its profits to the British government, for administration of the British Indian Ocean Territory. After being questioned as a result of the interview, the British Government denied receiving any funds from the sale of .io domain names, and argued that consequently, the profits could not be shared with the Chagossians, the former inhabitants forcibly removed by the British government.
Donuts acquired Afilias last month, and it made sense that Ethos was involved in the deal on the back end. Ethos had investors eager to put money to work in the domain name business after the .org deal fell through. Akram Attallah, CEO of Donuts, told me today that the company’s main focus going forward is working on the integration of Afilias.
Question (Asked by Lord Avebury): What plans have Her Majesty’s Government to share the revenues from the sale of the domain name .io with the people of the Chagos Archipelago including the descendants of those who were evicted from the islands? Answer: The Senior Minister of State, Department for Communities and Local Government & Foreign and Commonwealth Office (Baroness Warsi): 'In much the same way as the .uk domain, the administration of the .io domain has always been carried out by a private sector organisation – this is currently the Internet Computer Bureau. As with the .uk domain, the Government receives no revenues from the sales or administration of this domain, and there are therefore no plans to share these with Chagossians.'
There is no agreement between the UK Government and ICB regarding the administration of the .io domain. ICB independently registered the .io domain through the internet governing process – the Internet Assigned Numbers Authority (IANA) – in the late 1990s. Neither the UK Government nor the BIOT Administration receives revenue from the sale of .io domains, which are administered independently by ICB.
There's lots of open source projects (Redis, Brackets, Launcher), a few mobile-app landing pages (Avocado, X-Ray), a ton of new web apps and services, several conference pages (Lightning, Renaissance, Resonate) and a few older companies or organizations who've changed their name to take advantage of a cleaner .io name.