.io

Introduced	1997
TLD type	Country code top-level domain
Status	Active
Registry	NIC.IO (run by Internet Computer Bureau)
Sponsor	IO Top Level Domain Registry (Cable and Wireless)
Intended use	Entities connected with  British Indian Ocean Territory
Actual use	Popular with startup companies; little of 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
DNSSEC	yes
Registry website	NIC.IO

.io is the Internet country code top-level domain (ccTLD) for the British Indian Ocean Territory. A domain name is an identifier for an internet resource, e.g. a website, and exists so that users do not have to remember numerical IP addresses that are used between computers. Internationalized domain names may also be registered.^[1]

The .io domain name is administered by the Internet Computer Bureau, a company based in the United Kingdom.^[2]

Other than the Diego Garcia atoll, the territory has been uninhabited since the existing population was evacuated in 1973 and has no government of its own. Google currently treats .io as a generic top-level domain (gTLD) because "users and webmasters frequently see [the domain] more generic than country-targeted".^[3]

The .io domain extension has existed since 1997, and has grown steadily in popularity ever since. .io domains now compose 0.1% of all websites.^[4]

The first IO-related domain to be registered was the domain data-io.com, which when it was registered in late 1986 was the 45th domain name ever to be registered.^[5]

The first .io-domain was not registered until 1998, when Yahoo Inc registered the domain yahoo.io.^[6]

The following table lists some of the first .io-domains to be registered:^[7]

Labels for .io domains may only contain alphabetical characters and must be between 3 and 63 characters long, and can only contain the following characters: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 0 1 2 3 4 5 6 7 8 9 -. Domain names can not begin with, or end with, a hyphen symbol, but may not conatin to consecutive hyphens.^[8][9] The entire domain name may not contain more than 253 characters.^[10]

The right to administer domain names is given to approved organisations by the Internet Society. The Internet Computer Bureau administers .io domains. The Internet Computer Bureau is a Brittish company that, in addition to the right to sell .io-domains, also holds the right to sell .sh-domains and .ac-domains, the top-level domains for Saint Helena and the South Atlantic islands of Ascension.^[11][12]

Both individuals and organisations are allowed to register .io-domains.

In order to register .io domains you must not be registered or established in the British Indian Ocean territory. In order to register third-level domains such as xyz.com.io you have to be an inhabitant of the area. Any second-level domains used by NIC.IO and top-level domains can not be used as a third-level domain. For example the domain "com.com.io", "org.com.io" and "biz.com.io" are all restricted.^[13]

.io domains may not be used "for any purpose that is sexual or pornographic or that is against the statutory laws of any Nation". Breaching this this requirement "NIC.IO reserves the right to immediately deactivate the offending registration".^[13]

.io domains may be registered for a minimum of one year, and a maximum of 10 years.^[14]

.io-domains are currently priced higher than many other domains, partly due to high demand. Registering available .io-domains starts from around 30£ per year.^{[13] [15]}

To many the .io-domain is used with little thought of its origin.

"Nowadays, a lot of TLDs are used without any relation to the original country, such as .ly, .io, .me."

— Jens Segers - Founder of Auki.io, [[1]]

IO is also commonly used in IT as an abbreviation for input/output, which makes the .io domain useful for domain hacks and services wanting to be associated with technology.^[16]

"We took it because it refers to ‘input-output’. And our customers (mostly tech savvy people) understand it like so."

— Ben Verbeken - Seats.io CEO, [[2]]

Due to its lack of geographical association, and its reminiscent of Input/Output, .io domains have become a popular alternative for startup companies.^[17][18]

IO also stands as an abbreviation for Internet Organization^{[citation needed]}. In addition, .io domains are often used for open source projects, APIs (such as put.io API and pen.io API) and online services.^[19]

As with most domains a lot of domains are being bought without being used for websites. There is no exact figure of how many of the .io-domains that have been bought that are actually in use, but there have been multiple cases in which .io-domains have been sold for substantial amounts of money.

This table lists some .io-domains that have recently successfully been sold :^[20]

One of the main reasons behind this popularity is the availability of .io domains. Whereas it is often hard to find a fitting .com domain there are plenty .io domains available that have not yet been registered. The relatively high price of .io domains is likely one reason there are many .io domains left to register.

218 out of the million most popular websites use a .io-domain. These are the most popular domains using the .io domain extension.^[18]

The Internet Computer Bureau is required to give some of its profits to the British government, and then invests the rest in the DNS system.^[12]

Each of Britain's overseas territories has an account which the British government puts money into for administration of the territories, and the profits from the .io domain names offset this cost.^[12] However, due to the British expulsion of the native population from the territory, no indigenous Chagossians remain in the territory, the only residents being about 4000 United States military personnel and contractors.^[21] For this reason, the indigenous Chagossians do not receive any monetary benefit from the sale of the domain names.

The sale of .io domain names has become a point of contention between Chagossians and the British.

"I am afraid that this is another example of the Chagossian people being robbed — when there were tuna fishing licences for sale the exiled Chagossians saw none of the profits, nor any of the tourist fees, nor of course the billions of pounds of rent paid by the U.S. military for leasing our homeland."

— Sabrina Jean - Chair of the U.K. Chagos Support Association, [[3]]

The president of the Diego Garcia and Chagos Islands Council, Allen Vincatassin, has stated that "we do not know what sort of income is being received from the sale of these internet domains and to what use it is being put", calling upon the U.K. to provide transparency in the process.^[22]

• IANA .io whois information
• Internet Society website
• NIC.IO
• Gigaom