The job involves all the process from investigation to decisions and policy planning. As the job deals with the fiscal policy and budget, aptitude for accounts as well as a legal aptitude is useful. The professional training is conducted in the National Academy of Direct Taxes, Nagpur and the probationer will also receive on the job training at an Assistant Commissioner’s office for sometime. Following this they will serve as an Assistant Commissioner for eight years. They will examine cases in which the tax assessed is more than the prescribed figure. Assistant Commissioner deal with income and losses between Rs 2-5 lakhs .In the junior Administrative Grade (JAG) and Selection Grade they would be a Deputy Commissioner of Income Tax or Deputy Director (Investigation ). Deputy Commissioner (Assessment) handles cases above Rs 5 lakhs. In the senior Administrative Grade they could be a Commissioner of Income Tax in a metropolitan town or one of the state capitals or a Director of Income Tax. Some of these Commissioners are designated as Chief Commissioners of Income Tax and  are in a scale similar to that of Additional Secretaries. The Director General of Income Tax is also in this scale.   The head of the Income Tax hierarchy is the chairman of the Central Board of Direct Taxes and is assisted by six members.

The Indian Revenue Service (IRS) is one of the Premier Civil Services (Group "A") of India. IRS comprises IRS(C&CE) & IRS (IT). IRS officers are concerned with the collection, administration and policy formation of direct (viz. Income, Corporate, Wealth, FBT etc.) & indirect (viz. Central Excise, Service Tax and even Customs Duty) taxes. These officers are the tax administrators of the union of India. They are either under the Central Board of Direct Taxes (CBDT) or Central board of Excise & Customs (CBEC) in the Department of Revenue under the Ministry of Finance.

IRS Officer Trainees (OTs, as they are fondly referred to) undergo a 3 month foundational training with their fellow officers from All India Services and other Central Services (Group A) at Lal Bahadur National Academy of Administration (LBSNAA) Mussoorie, (Uttarakhand) followed by a 15 month rigorous professional training in NACEN Faridabad for the officers of Customs and Excise or NADT, Nagpur for officers of Income Tax, where they are intensively trained in principles, concepts and advances in Management, Taxation. Public Policy and Law.

Starting with the post of Assistant Commissioner, IRS officers rise up to Chief Commissioner level with some fortunate ones reaching the post of Member/Chairperson - CBDT / CBEC. The Revenue Secretary who heads the Department of Revenue in the Ministry of Finance is usually an IAS officer. They are also deputed to the Vigilance Department, Enforcement Directorate, SEBI, Directorate of Revenue Intelligence, Narcotics Control Bureau, etc. apart from heading various cells in the Ministry of Finance. However the administrative acumen of the service has now started getting recognition of late. One of the previous Chief Election Commissioner was an IRS officer.
Career prospects

Though the pay is much lower than in private sector, given the high talent and intelligence of the recruits, the unparalleled power, perks, and prestige make up for it. Officers also feel an added sense of satisfaction that comes from directly contributing to the development of the country, revenue being the source of all developmental works of a government. Their contribution can be judged from the fact that with a total strength of around 5000 officers (in direct taxes) and an added 2500 (in indirect taxes), the IRS are responsible for collection of direct/indirect taxes worth tens of thousands of crores of rupees. Presently only 3% of Indian population comes in the direct tax bracket. Similarly the Service Tax has only started picking up of late due to very few services in the tax net. With the economy booming, the IRS is bound to play an increasingly important role in the affairs of the state. As the country liberalises further, the economic power will shift into private hands with the public-private participation being the keyword. Hence the IRS officers will be at the interaction point between the private industry and the government. Candidates prefer the IRS above other premier services due to relatively low political interference, greater leisure time, stable tenures, and postings to big cities.