Classification of Indian cities
The Classification of Indian cities comprises a ranking system used by the Government of India to allocate House Rent Allowance (HRA) to public servants employed in different cities in the country. HRA is also used by the Indian Revenue Service (IRS) to provide income tax exemptions. Cities are classified as X, Y and Z, on the basis of their population, as recommended by the Sixth Central Pay Commission in 2008.
Before the Sixth Central Pay Commission, the classification of cities in India was based on two parameters — Compensatory City Allowance (CCA), further divided into categories A-1, A, B-1 and B-2, and HRA, further divided into categories A-1, A, B-1, B-2 and C. This classification was initially based on the recommendations of the Fifth Central Pay Commission of India in 1997. Chennai, New Delhi, Kolkata and Mumbai were classified as A-1 cities. City statuses were later revised based on the results of the 2001 Census of India. Hyderabad was accorded the A1 status on 31 August 2007, and Bangalore on 21 September 2007.
Under the recommendation of the Sixth Central Pay Commission, the CCA classification was abolished in 2008. The earlier HRA classification of cities was changed from A-1 to X, A, B-1 and B-2 to Y and C and unclassified cities to Z.   X, Y and Z are more commonly known as Tier-I, Tier-II and Tier-III cities respectively.
|Z||All other cities|
The cities were classified as follows before the Sixth Central Pay Commission's recommendations were followed in 2008:
|CCA classification||HRA classification||City|
- "Sixth Central Pay Commission". Ministry of Finance. Retrieved 13 January 2013.
- "Sixth Central Pay Commission Classification of Cities". Ministry of Personnel, Public Grievances and Pension. Retrieved 26 March 2014.
- "Recommendations of the Sixth Central Pay Commission - Decision of Government relating to grant of Dearness Allowance to Central Government servants". Ministry of Finance Department of Expenditure. Retrieved 26 March 2014.
- "THE ALL INDIA SERVICES (HOUSE RENT ALLOWANCE) RULES,". Chhattisgarh State Government. Retrieved 26 March 2014.
- Upgradation of Greater Hyderabad Municipal Corporation as A-1 class city for the purpose of House Rent Allowance/Compensatory (City) Allowance". Department of Expenditure. Ministry of Finance. 10 October. 2007