Home / Comparisons / IBM MLC vs IPLA
① Comparison · IBM Licensing Models
MLC is a monthly recurring charge on the rolling four hour average. IPLA is a one time charge plus annual support. They are not competing choices, they are two models running side by side, and each has its own levers. Here is the head to head, buyer side.
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Get expert help →MLC and IPLA are not an either or choice; almost every z/OS estate runs both at once, and the win is knowing which lever fits which line. On MLC software, the cost moves with your monthly peak, so the levers are sub-capacity discipline, soft capping, zIIP offload, and a hard look at Tailored Fit Pricing baselines. On IPLA software, the cost was set at purchase, so the levers are rebaselining licensed capacity against what you actually run and capping Subscription and Support uplift year over year. Treating the whole IBM bill as one undifferentiated number is the mistake. Split it by model first, then pull the lever each model rewards.
The two models differ in when you pay, what the meter reads, and what moves the number. MLC is a recurring monthly charge on core z/OS software, billed on the peak rolling four hour average capacity. IPLA is a one time charge for a perpetual license, carried afterward as optional annual Subscription and Support, and priced through Value Units.
| Dimension | MLC (Monthly License Charge) | IPLA (Intl Program License Agreement) |
|---|---|---|
| Payment shape | Recurring monthly charge | One time charge plus optional annual S&S |
| What the meter reads | Peak rolling four hour average MSU for the month | Licensed capacity at purchase, in Value Units |
| Typical products | z/OS, CICS, Db2 for z/OS, IMS, MQ | Tools, utilities, security and monitoring add ons |
| Support | Included in the monthly charge | Separate annual Subscription and Support |
| Main cost driver | Monthly capacity peak and software running in it | Stated licensed capacity and S&S uplift |
| Primary levers | Sub-capacity, soft capping, zIIP, Tailored Fit Pricing | Rebaseline capacity, cap S&S, retire unused entitlements |
Directional comparison. Confirm each product's metric on your IBM agreement; an estate commonly mixes both models and a third path under Tailored Fit Pricing.
Sub-capacity reporting discipline through SCRT, so you are billed on the LPAR peaks that actually apply rather than full machine capacity. Soft capping and capacity management to shave the rolling four hour average where workloads allow. zIIP offload to move eligible work off general purpose engines. And a genuine evaluation of Tailored Fit Pricing, where the negotiated baseline is the whole game. These levers move a recurring charge, so the saving repeats every month for the life of the contract.
A rebaseline of licensed capacity and Value Units against the estate you run today, because IPLA capacity is a stated figure that rarely shrinks on its own after consolidation. A cap on the annual Subscription and Support uplift, which is the part that compounds. And retirement of entitlements you no longer use, since a perpetual license you have stopped running is still carrying S&S. The one time charge is sunk; the recurring S&S is where the negotiation lives.
MLC, Monthly License Charge, is a recurring monthly charge for core z/OS software such as z/OS, CICS, Db2, IMS, and MQ, billed on the peak rolling four hour average capacity used during the month with support included. IPLA, International Program License Agreement, is a one time charge for a perpetual license plus an optional annual Subscription and Support stream, used for tools and many add on products and priced through Value Units. The practical difference is that MLC cost moves with monthly usage while IPLA cost is set at purchase and then carried as annual support.
z/OS itself and the core subsystems that run alongside it (CICS, Db2 for z/OS, IMS, MQ) are MLC products billed monthly on the rolling four hour average. Many of the tools and utilities around them, including security and monitoring add ons, are IPLA products carried as a one time charge plus annual Subscription and Support. A typical estate runs both models at once, which is why the optimization levers differ line by line.
Neither is cheaper in the abstract; they bill differently. MLC is sensitive to your monthly peak, so it rewards sub-capacity discipline, soft capping, and zIIP offload that pull down the rolling four hour average. IPLA is set at purchase and rewards rebaselining the licensed capacity and challenging Subscription and Support uplift over time. The right question is not which model is cheaper but which lever moves the specific line you are renewing.
Tailored Fit Pricing is an alternative MLC pricing approach, not a separate license agreement. It moves eligible MLC software off the monthly rolling four hour average and onto a consumption or committed baseline model. It does not change IPLA products, which remain one time charge plus Subscription and Support. Evaluating a move to Tailored Fit Pricing is an MLC decision, and the baseline you commit to is the thing to negotiate hard.
Related concept: Monthly License Charge explained and Subscription and Support on the mainframe. Related comparison: Tailored Fit Pricing vs sub-capacity. Publisher hub: IBM mainframe licensing. Put it to work: IBM cost optimization.