|Introduced||19 December 1997|
|TLD type||Country code top-level domain|
|Registry||Ascension Island Network Information Centre (run by Internet Computer Bureau)|
|Sponsor||Cable and Wireless (Ascension Island)|
|Intended use||Entities connected with Saint Helena, Ascension and Tristan da Cunha|
|Actual use||Various uses, sometimes connected to education and academia; a few sites actually on Ascension Island|
|Registration restrictions||2nd-level registrant must have professional or academic qualification; 3rd level registrant must be resident on Ascension Island|
|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 .ac top-level domain is the Internet country code (ccTLD) for Saint Helena, Ascension and Tristan da Cunha, and primarily for Ascension Island. It is administered by NIC.AC, a subsidiary of the Internet Computer Bureau based in the United Kingdom.
Use as an abbreviation for "academic"
- The University of Kurdistan - Hawler
- Ralston College in Savannah, Georgia, United States
- Faith Mission Bible College in Edinburgh, Scotland
- It is also used for promotion, campaigns, and URL shortening by various parts of the University of Edinburgh, Scotland
- The Mahidol Oxford Tropical Medicine Research Unit (MORU) in Bangkok, Thailand
- INFORM (Information Network Focus on Religious Movements), based at the London School of Economics
- Newcastle University, an online university unconnected with Newcastle University in the United Kingdom or the University of Newcastle, Australia
- Dhaka International University in Dhaka, Bangladesh
- On 10 December 2013, The Pirate Bay switched to an .ac domain.
- .ac is being used by anti-cheat software Easy Anti-Cheat.
- .ac is occasionally used as an abbreviation for activities and/or accommodation by tourism websites.
- "IDN Code Points Policy for the .AC Top Level Domain" (PDF). nic.ac. 2013-05-20. Archived from the original (PDF) on 2014-08-06. Retrieved 2013-05-23.
- "University of Kurdistan Hewlêr". Archived from the original on 2012-10-30. Retrieved 2009-04-01.
- "Collegium Ralstonianum apud Savannenses - New Website Under Construction". Archived from the original on 2019-04-16. Retrieved 2021-03-30.
- "Faith Marketing Business Consulting | Faith Based Marketing". Archived from the original on 2021-01-22. Retrieved 2021-03-30.
- "University of Edinburgh". edin.ac.
- https://switch.ac[permanent dead link]
- "Home - Mahidol Oxford Tropical Medicine Research Unit". Archived from the original on 2021-03-08. Retrieved 2021-03-30.
- "New Religious Movements - Latest news from Inform | Inform". Archived from the original on 2021-03-09. Retrieved 2021-03-30.
- "Newcastle". Archived from the original on 2019-09-21. Retrieved 2012-01-17.
- "DIU | Dhaka International University". Retrieved 2021-08-04.
- "The Pirate Bay Moves to .AC After Domain Name Seizure". 2013-12-10. Archived from the original on 2013-12-10. Retrieved 2013-12-10.
- "Easy Anti-Cheat". Archived from the original on 2021-02-17. Retrieved 2021-03-28.
- ""Melbourne - Activities & Accommodation"". Retrieved 2021-06-04.