SAP first communicated the December 2025 sunset of Compatibility Pack usage rights more than five years ago, in SAP Note 2269324. Customers have known the deadline. Their partners have known it. The user groups — ASUG, DSAG, UKISUG — have published explainers about it for nearly as long as the note has existed. In December 2025, with what SAP called a final five-month transition period, the deadline shifted from December 31, 2025 to May 31, 2026. Five additional months is what the field has been working with. That window closes in twenty-nine days.
If you are a CIO, finance director, or program manager at an organization still on S/4HANA on-premise with active dependencies on Compatibility Pack functionality, you already know whether the next four weeks are going to feel like the run-up to a controlled go-live or like a fire drill. This essay is for you, and especially for the version of you that is going to be in the meeting on June 1 explaining why some particular thing didn't get done. It is about how to think about the remaining month, what reasonable triage looks like, and what almost every organization is getting wrong about how to make these decisions under pressure.
What Compatibility Packs are, briefly
For readers who have not been living inside this problem: Compatibility Packs are a transitional licensing construct. When SAP launched S/4HANA, it could not, in any reasonable amount of time, replace the entire surface area of classic ECC functionality with native S/4HANA equivalents. Some pieces — Customer Service (CS), Logistics Execution and Transportation (LE-TRA), Production Planning for Process Industries (PP-PI), large parts of Order Management, Material Ledger logic, certain reporting transactions — were either not yet replatformed or replatformed in ways that would have stranded existing customers. The Compatibility Pack mechanism gave those customers temporary, time-limited usage rights to keep running the classic ECC code paths inside an S/4HANA system, while SAP and its partners developed transition guides toward the native S/4HANA equivalents.
Two things are worth saying clearly about that mechanism. First, it was always temporary by design. The expiration dates are not a surprise sunset; they are the original product of a deliberate, documented, multi-year communication program. Second, what expires is the licensing right, not the technical functionality. After May 31, the code does not stop running. The contractual permission to run it does. Continued use becomes, in SAP's own framing, commercially unlicensed — which, in plain language, means SAP can audit you, charge you, and use the finding as leverage in renegotiation.
The CS, LE-TRA, and PP-PI carve-outs run until December 31, 2030, and customers on RISE with SAP (now branded SAP Cloud ERP private) operate under a separate clock. If your organization is in either category for all of its Compatibility Pack dependencies, you have time and you can stop reading. Most readers of this piece are not in either category for all of their dependencies. They have a mix.
What's actually breaking on June 1
Almost everyone telling you about this deadline is telling you the same three things: do an inventory, prioritize remediation, plan a transition. That is correct advice the way "exercise more and eat better" is correct advice. It is true. It is generic. It is not why programs fail in the next four weeks.
The actual failure modes I have observed and read about cluster around three specific patterns, and none of them are technical.
The actual failure modes are not technical. They are organizational misjudgments about which problems are deadline problems and which problems are budget problems and which problems are political problems pretending to be either of the first two.
The first pattern is treating this as a remediation project when it is a process redesign decision. When a Compatibility Pack expires, the native S/4HANA replacement almost never has the same data model, the same UI, the same transaction codes, or the same exception-handling semantics as the classic functionality. The decision is not "remediate the legacy function." The decision is "redesign the business process around the new functional capability, including all the workarounds and edge cases your operations team built up over fifteen years of working with the old one." Programs that treat the work as the former produce technically successful migrations that operations teams refuse to use. We have a fairly thorough literature on this dynamic. It is the adoption gap I wrote about last week.
The second pattern is misjudging which legacy dependencies are actually core. Many organizations enter the final months with a Compatibility Pack inventory that was produced during a Readiness Check eighteen months ago and has not been re-validated. Functions that the inventory identified as low-impact have, in the intervening time, become woven into accounting reconciliations, regulatory reports, or supply-chain integrations that the inventory's authors did not know existed. Conversely, functions that the inventory called critical have, in some cases, been quietly retired by the business, or have shrunk to a single edge case that does not justify the remediation cost. The inventory is older than the business it describes. Re-validate it. This week. Walk it physically with the people who use the function. Do not rely on the document.
The third pattern is under-budgeting for change enablement on the new functionality. The dollars budgeted for transitioning off a Compatibility Pack typically cover the technical move, the testing, and the cutover. The dollars not budgeted typically cover what to do when the operations team, six weeks after go-live, is still calling the old transaction names and pasting screenshots of the legacy interface into Slack messages asking how to reproduce its behavior in the new one. Budgets that do not include three to six months of structured user-side enablement after go-live consistently underestimate the cost of adoption by 30 to 60 percent. There is no shortcut here. There never has been.
What good triage looks like, in the next four weeks
I am going to resist the temptation to give you a generic eight-step plan, because eight-step plans are what got us into the failure modes above. Instead, I will describe how I would think about the time remaining, and you can adapt it to your situation.
The first thing I would do is separate three categories of dependencies, deliberately. Category one: dependencies on Compatibility Packs whose expiration is May 31, 2026. Category two: dependencies on the CS, LE-TRA, or PP-PI carve-outs. Category three: dependencies on functionality that is in your inventory as a Compatibility Pack item but is, on closer inspection, no longer actually in use. The third category is the easiest to underestimate. Many organizations have inventory entries that have not been used in production for six months because the underlying business process changed and nobody updated the inventory. If you can credibly retire those, you have just reduced the deadline scope.
For what remains in category one, I would split into two further buckets. Bucket A: dependencies where the SAP-native replacement is in place, has been tested, and the work remaining is cutover plus enablement. Bucket B: everything else. Bucket A is a project management problem with known levers. Bucket B is the bucket where you make the hard decisions.
For Bucket B, the question is no longer "how do we transition?" It is "what is our compliance posture and what is the cost of being on the wrong side of the deadline?" Honest answers to that question are uncomfortable but necessary. SAP's negotiating posture after the deadline, based on what people I trust have observed in similar audit cycles, is materially less flexible than its negotiating posture before. The leverage shifts. If you are going to be in compliance discussion with SAP after June 1, doing the strategic work of the conversation in May — specifically, figuring out what your offer looks like — is significantly cheaper than reacting to whatever SAP opens with in July.
What this tells us about the 2027 deadline
The Compatibility Pack deadline is, in the larger arc of the SAP transition cycle, a small event. The defining event is December 31, 2027, when SAP ECC mainstream maintenance ends and the substantive migration cliff arrives. The Compatibility Pack situation is a useful diagnostic for the larger one in two specific ways.
First, it tells us how organizations behave when they have known about a deadline for years and still arrive at the last month with incomplete plans. The answer, with very little variation across the firms I know, is: the deadline is treated as advisory until roughly nine months out, then as urgent until roughly three months out, then as panic-inducing in the final ninety days. The organizational machinery does not seem capable of metabolizing five-year deadlines as five-year work. The work happens in the panic window.
Second, it tells us where the constraints are. The constraint on Compatibility Pack remediation in the last month is rarely the technical work. It is consulting capacity, internal change-enablement capacity, and decision-maker bandwidth. All three of those are about to be dramatically more constrained eighteen months from now, when the much larger ECC sunset arrives. Programs that are in panic mode this May will be in catastrophic mode in late 2027 unless something structural changes about how they plan.
The structural change I would advocate for is straightforward: stop treating these deadlines as technical project deadlines and start treating them as adoption deadlines. The technical work fits in the final year. The adoption work does not. Every program that successfully landed a major SAP migration in the last five years started its serious adoption planning at least eighteen months before go-live. Every program that landed badly started it later than that.
One last thing
If you are reading this in May 2026 and your organization is genuinely going to miss the May 31 deadline on a non-trivial piece of Compatibility Pack functionality, my honest advice is to spend the next two weeks on the conversation you are going to have with SAP, not on the conversion itself. Document what you have done. Document what you have not done. Document what your remediation plan looks like and the timeline you commit to. Bring that document to the conversation. SAP audit conversations are very different when the customer enters them with a credible plan than when the customer enters them defensive.
And then, when this deadline is past, I would do something else. I would convene the program leadership in early June and conduct a frank retrospective on the question of why a deadline you knew about for five years became a fire drill in the final month. The answers to that retrospective are the answers that will determine whether your 2027 program lands or burns. The May 31 deadline is small enough to recover from. The December 2027 one is not.
Ikechukwu Ohu, PhD is an independent consultant working on enterprise process, adoption, and human factors. He spent three and a half years as a UX Researcher in AWS Fintech R&D and is Full Professor and Program Director of Industrial & Robotics Engineering at Gannon University. He is currently certifying in SAP S/4HANA Cloud Public Edition Financial Accounting. Reach him at ohu@pinohu.com.