IBM i Licensing Explained
IBM i licensing is tied to the processor tier of the underlying IBM Power hardware, not just to core count or user seats. Understanding software tiers, program license terms, and how licensing carries across a hardware upgrade is essential before budgeting a Power Systems project.
IBM i licensing does not work like most enterprise software, where cost scales with seats or a flat server fee. It is tied to the processor capacity of the specific IBM Power hardware the OS runs on, which means a hardware sizing decision and a licensing decision are really the same decision. This trips up organizations evaluating an upgrade for the first time in years, since the licensing math looks different than what they remember from their last purchase.
Processor-Based Software Tiers
IBM groups Power Systems hardware into software tiers, commonly referenced as P05, P10, P20, P30, P40, and P50, based on the system's maximum CPW rating. IBM i base OS licensing, and much of the IBM i software ecosystem including many third-party ISV products, is priced against this tier rather than against raw core count. See IBM Power sizing basics for how tier selection interacts with hardware sizing.
Program License Terms
IBM i software, including the base operating system and licensed program products (LPPs) such as additional language compilers or specific feature sets, is delivered under IBM's standard Program License Terms. Some IBM i features and LPPs are included with the base OS at no additional charge, while others are separately orderable. Understanding which features are already entitled under a current license, versus which require a separate order, is a common gap in IBM i licensing reviews.
User-Based Entitlements
Beyond the processor tier, some IBM i software, particularly interactive and 5250-related licensing historically, has involved user or connection-based entitlements. Modern IBM i licensing has moved away from strict per-user interactive limits toward capacity-based models, but organizations with long-running contracts should verify their specific entitlement terms rather than assume current licensing rules apply retroactively to legacy agreements.
Licensing and Hardware Upgrades
Moving IBM i to new Power Systems hardware, such as a Power9 or Power10 to Power11 migration, generally requires evaluating whether the new hardware's software tier matches, exceeds, or falls below the current license entitlement. A processor upgrade that crosses into a higher tier (for example, moving from a P10 to a P20 configuration) increases IBM i licensing cost, sometimes significantly, independent of the hardware price itself. This is why tier boundaries are a standard checkpoint in any Power Systems upgrade proposal, not an afterthought.