Idea Cellular Limited (commonly referred to as Idea, and stylised as !dea) was an Indian mobile network operator based at Mumbai, Maharashtra. Idea was a pan-India integrated GSM operator and had 220.00 million subscribers as of June 2018. Idea Cellular merged with Vodafone India and now both companies called Vodafone Idea. 
|Fate||Merged with Vodafone India|
|Successor||Vodafone Idea Limited|
|Defunct||31 August 2018|
|Headquarters||Gandhinagar, Gujarat, India|
|Kumar Mangalam Birla (Chairman) Himanshu Kapania (Managing Director)|
|Products||Mobile telephony, wireless broadband|
|Revenue||₹35,475.7 crore (US$5.0 billion) (2016)|
|₹10,291.9 crore (US$1.4 billion) (2016)|
|₹−831.1 crore (US$−120 million) (2016)|
|Members||220.00 million (June 2018)|
|Parent||Aditya Birla Group|
Idea Cellular was incorporated as Birla Communications Limited in 1995 after GSM licenses were won in Gujarat and Maharashtra circles. The company name was changed to Idea Cellular and the brand Idea was introduced in 2002 after a series of name changes following mergers and joint ventures with Grasim Industries, AT&T Corporation and Tata Group. Following the exit of AT&T Corporation and Tata Group from the joint venture in 2004 and 2006 respectively, Idea Cellular became a subsidiary of Aditya Birla Group. Malaysia based Axiata had bought around 20% stake in the company in 2008 for 2 billion USD.
Idea previously bought a 40.8% stake in Spice Communications Ltd, operating as Spice Telecom, for over Rs 2,700 crore.
Merger of Vodafone and Idea (Vi)Edit
The entry of Jio in 2016 had led to various mergers and consolidations in the Indian telecom sector. It was announced in March 2017 that even Idea Cellular and Vodafone India would be merged. The merger got approval from Department Of Telecommunications in July 2018. On August 30, 2018, National Company Law Tribunal gave the final nod to the Vodafone-Idea merger  The merger was completed on 31 August 2018, and the newly merged entity was named Vodafone Idea Limited. The merger created the largest telecom company in India by subscribers and by revenue. Under the terms of the deal, the Vodafone Group holds a 45.2% stake in the combined entity, the Aditya Birla Group holds 26% and the remaining shares will be held by the public.
After merge, Vodafone and Idea is known as Vi. It was a biggest combination between two telecom companies in the world.
On 7 September 2020, Vodafone Idea unveiled its new brand identity, 'Vi' which involves the integration of the company's erstwhile separate brands 'Vodafone' and 'Idea' into one unified brand.
In the 2010 3G spectrum auction, Idea paid ₹57.68 billion (US$810 million) for spectrum in 11 circles. After the launch of MNP in India, Idea further strengthened its customer base because it was the mobile network with most net port-ins.
Radio frequency summaryEdit
Note: The above table contains Vodafone-Idea (merged entity) radio frequency details because they used to share their networks with each other via ICR (intra-circle roaming agreement) in some circles. For example, Idea had started giving its customers in Delhi access to 4G services in May 2018 via the Vodafone network. 
- Parbat, Kalyan; Sengupta, Devina (31 August 2018). "NCLT gives go-ahead to Idea-Vodafone merger". The Economic Times. Retrieved 1 September 2018.
- "Idea Cellular – Cell Phone Services". Retrieved 28 June 2012.[permanent dead link]
- "Consolidated Result 2016-17".
- "Idea Cellular Limited: Private Company Information". bloomberg.com. Retrieved 3 August 2018.
- "Press Release No. 23/2018" (PDF). Telecom Regulatory Authority of India. 16 February 2018. Retrieved 20 February 2018.
- "Idea-Vodafone say merger complete, now India's largest telco with 408 million active users". Indiatimes. 31 August 2018.
- "Cingular Allows Agreement to Sell Stake in Indian Wireless Service Provider to Expire". U.S. Securities and Exchange Commission. Retrieved 7 June 2015.
- www.ETTelecom.com. "Malaysian Telco Axiata may soon exit Vodafone Idea as stock continues its slide - ET Telecom". Retrieved 14 June 2020.
- Kumar, Arun (30 June 2008). "Spice Telecom buy to leave Idea Cellular richer". Hindustan Times. Retrieved 21 December 2020.
- Raj, Amrit (21 October 2017). "The shakeup in India's telecom sector". www.livemint.com. Retrieved 21 April 2018.
- "Idea approves merger with Vodafone India, to create India's largest telco". The Economic Times. Retrieved 20 March 2017.
- Kurup, Rajesh (20 March 2017). "Idea Cellular board approves merger with Vodafone India; shares tank 9%". The Hindu Business Line. Retrieved 20 March 2017.
- "Disclosure under Regulation 30 of SEBI (LODR) Regulations, 2015" (PDF). BSE. BSE. Retrieved 31 August 2018.
- Pahwa, Nikhil (19 May 2010). "India's 3G Auction Ends; Operator And Circle-Wise Results". MediaNama.
- Abbas, Muntazir (13 April 2016). "Five years on, Idea, Vodafone, Airtel emerge top gainers in MNP: Kotak". The Economic Times. Retrieved 21 April 2018.
- Pan India 2016 spectrum holding data sheet (updated), Telecom Talk, retrieved 15 July 2018
- Idea Cellular 4G Services Now Live in Delhi Via ICR With Vodafone, Telecom Talk, retrieved 15 July 2018
- Idea to launch VoLTE in March, inks 4G ICR agreement with Vodafone, ET Telecom, retrieved 15 July 2018