| Abbreviation | Definition |
|---|---|
| IRBA | Independent Regulatory Board for Auditors |
| IRBA | Independent Regulatory Board for Auditors (South Africa) |
| IRC | International Reply Coupon |
| IRC | Item Related Check |
| IRCA | International Register Of Certificated Auditors |
| IRD | Income in Respect to Decedent |
| IRE | Institut des Reviseurs d'Enterprises (Belgium) |
| IRG | Interest Rate Guarantee |
| IRP | Intermediary Relending Program |
| IRR | Internal Rate of Return |
| IRS | Increasing Returns to Scale |
| IS | Income Statement |
| ISA | Individual Savings Account |
| ISA | International Safety Auditors |
| ISA | International Standard of Auditing |
| ISA | International Standard on Auditing |
| ISACA | Information Systems Audit and Control Association (USA) |
| ISAR | International Symposium on Audit Research |
| ISBA | Idaho State Board of Accountancy |
| ISBP | International Standard Banking Practice |