| AIR | Annual Information Return | A |
| AJP | Artificial Jurisdical Person | |
| AO | Assessing Officer | |
| AOP | Association of Persons | |
| ATM | Automated Teller Machine | |
| AY | Assessment Year | |
| BOI | Body of Individuals | B |
| BSR | Basic Statistical Return | |
| CCIT | Chief Commissioner of Income Tax | C |
| CA | Chartered Accountant | |
| CBDT | Central Board of Direct Taxes | |
| CCA | Controller of Certifying Authorities | |
| CDSL | Central Depository Services (India) Ltd | |
| CIN | Challan Identification Number | |
| CPC | Centralized Processing Centre | |
| DOI | Date of Incorporation | D |
| DGIT | Director General of Income Tax | |
| DOB | Date of Birth | |
| DSC | Digital Signature Certificate | |
| DTAA | Double Tax Avoidance Agreement | |
| e-Pay | Electronic Payment | E |
| ECS | Electronic Clearing Service | |
| ERI | e-Return Intermediary | |
| EVC | Electronic Verification Code | |
| FAQ | Frequently Asked Questions | F |
| FRS | Functional Requirement Specification | |
| F&SRS | Functional and Software Requirement Specification | |
| FY | Financial Year | |
| HP | House Property | H |
| HTTP | Hypertext Transfer Protocol | |
| HTTPS | Secure Hypertext Transfer Protocol | |
| HUF | Hindu Undivided Family | |
| ITDREIN | Income Tax Department Reporting Entity Identification Number | I |
| ITR | Income Tax Return | |
| ITR-V | Income Tax Return Verification | |
| JSON | JavaScript Object Notation | J |
| LLP | Limited Liability Partnership | L |
| NCLT | National Company Law Tribunal | N |
| NMS | Non-filers Monitoring System | |
| NRI | Non-Resident Indian | |
| NSDL | National Security Depositary Limited | |
| OTP | One Time Password | O |
| PAN | Permanent Account Number | P |
| PFMS | Public Financial Management System | |
| POA | Power of Attorney | |
| QR | Quick Response | Q |
| SFT | Statement of Financial Transaction | S |
| TAN | Tax Deduction and Collection Account Number | T |
| TCS | Tax Collected at Source | |
| TDS | Tax Deducted at Source | |
| TRACES | TDS Reconciliation, Analysis and Correction Enabling System | |
| UM | User Manual | U |
| UIDAI | Unique Identification Authority of India | |
| USB | Universal Serial Bus | |
| XML | Extensible Markup Language |