Indian Revenue Service

The Indian Revenue Service (IRS), is the administrative revenue service of the Central Civil Services of the Government of India.
It is the largest Group A Central Service among st the organised civil services in the Government of India.
The Service functions under the Department of Revenue in the Union Ministry of Finance and is concerned with the collection and administration of the various direct and indirect taxes accruing to the Union Government.

IRS comprises two branches – IRS and IRS (Customs and Central Excise), which are controlled by two separate statutory bodies, viz., Central Board of Direct Taxes (CBDT) and Central Board of Excise and Customs (CBEC) respectively.
IRS serves the nation through discharging one of the most important sovereign functions i.e., collection of revenue for development, security and governance.

The procedure for becoming IRS Officer is the same as that of being IAS. It is just the difference about rank and preferred service cadre to choose for the different fields offered by the UPSC.

To become IRS officer you need to pass UPSC Civil Service Exam.
The UPSC Civil Service Exam consists of 3 stages and they are Preliminary Exam, Mains Exam, and Personality Test/Interview.

UPSC Exam details:

The competitive examination comprises two successive stages:
I. Civil Services (Preliminary) Examinations (Objective Type) for the selection of candidates for Main Examination; and
II. Civil Services (Main) Examination

For details click http://eloksevaonline.com/competitive-exams/civil-services-examination-pattern/.

Nationality:
For IRS a candidate must be a citizen of India.

Age Limit:
Age must be between 21 to 30 for General category.
Candidates of SC/ST and OBC will get extra age 5 and 3 years respectively.

Level and Rank:

• Assistant Commissioner of Income Tax / Entry-level (Probationer)
• Deputy Commissioner of Income Tax (Equivalent to) Under Secretary to Government of India
• Joint Commissioner of Income Tax (Equivalent to) Deputy Secretary to Government of India
• Additional Commissioner of Income Tax (Equivalent to) Director to Government of India
• Commissioner of Income Tax/Additional Director General (Equivalent to) Joint Secretary to Government of India
• Principal Commissioner of Income Tax (Equivalent to) Additional Secretary to Government of India
• Chief Commissioner/Director General (Equivalent to) Additional Secretary to Government of India
• Principal Chief Commissioner of Income Tax (Equivalent to) Special Secretary to Government of India
• CBDT Chairman/Member CBDT/DG Central Economic Intelligence Bureau (Equivalent to) Secretary to Government of India