[6] Officers from the Imperial Civil Services (ICS) manned top posts, and the lower echelons were filled through promotions from the ranks.

After selection, successful candidates undergo a 3-month Foundation Course at the Lal Bahadur Shastri National Academy of Administration (LBSNAA) in Mussoorie, Uttarakhand.

[8] Thereafter, IRS (IT) Officer Trainees (OTs) undergo a 16-month specialised training at the National Academy of Direct Taxes (NADT), in Nagpur, Maharashtra.

The training is designed as two modules in order to enable the Officer Trainees to acquire the knowledge and skills they need to function effectively and efficiently as tax administrators.

In particular, training prepares OTs to deliver quality taxpayer services, detect and penalize non-compliance, and understand the macroeconomic, taxation, and fiscal policy of the Government of India in order to maximize revenue.

[12] OTs also undergo short-duration training at NACIN, Faridabad, LBSNAA, Mussoorie, and the Sardar Vallabhbhai Patel National Police Academy (SVPNPA), Hyderabad.

[12][14][15] OTs are also trained to apply theoretical concepts and acquire practical skills through the subjects of Procedure/Techniques of Investigation and Drafting of Orders and Reports, Information Technology and Operations, Management and Administration in the Income Tax department, International Taxation and Transfer Pricing, Law of Governance and Ethics, and Business Laws-II.

[13][14][16] The designations and time-scales within the Indian Revenue Service are as follows after cadre restructure:[17] In 2015, it was reported that as many as 108 IRS officers were under probe by the CBI for their alleged involvement in corruption.

[25] Recently, in another case, some IRS officials were found to help certain companies evade payment of Service tax and related penalties of the order of ₹1 crore.

[26] Also CBI raided premises of an income tax officer for demanding Bribe to the tune of ₹60 crore for covering up Stock Guru Scam.

Refund Banker Scheme introduced in 2007, Introduction of E-filing of Taxes after 2009, effective implementation of Permanent Account Number (PAN), Centralized Processing Center setup in 2010 at Bangalore and subsequent e-processing of returns, e-assessments, faceless assessments etc.