The deadline most companies are underestimating
SAP has confirmed that mainstream maintenance for SAP ECC 6.0 will end in December 2027. This is not a soft deadline. Rimini Street confirmed in 2025 that SAP will not extend the ECC mainstream maintenance end date. The date stands.
According to Gartner data cited by CIO Magazine, at the end of 2024, only 39% of the 35,000 SAP ECC customers, roughly 14,000 companies, had completed their migration to S/4HANA. At current pace, Gartner projects approximately 17,000 companies will still be running ECC when maintenance ends in 2027. That's nearly half the global ECC customer base.
And here is the critical timing problem: a standard enterprise S/4HANA migration takes 12 to 18 months from project kick-off to go-live. Add 2 to 3 months for assessment and procurement, and organisations that haven't started by mid-2026 are no longer planning a migration before the deadline. They are planning what happens after it.
The Sparagus read: For many Belgian companies, the 2027 deadline is still treated as a future problem. It isn't. It's a 2026 resourcing and governance decision. Every month without a committed project plan narrows the options and increases the cost.
What end of maintenance actually means for your business
End of mainstream maintenance does not mean SAP shuts down overnight. Your system will keep running. But here is what changes immediately:
- No new legal and regulatory updates. Tax changes, payroll legislation, GDPR adjustments, e-invoicing requirements: if these affect ECC after 2027, SAP will not deliver the patches. Your team absorbs that cost manually or through third parties.
- No new security patches. Vulnerabilities discovered after the maintenance end date will not be remediated by SAP. On a system that processes your financial, HR, and supply chain data, this is a material risk.
- No functional improvements. Competitors running S/4HANA will continue receiving AI-powered analytics, embedded machine learning, and process automation. ECC customers will not.
- Compliance exposure. For companies subject to NIS2, GDPR, or sector-specific regulations, running an unpatched ERP creates audit and liability risk that will intensify over time.
Extended maintenance is available from SAP until December 2030, but at a cost. SAP Licensing Experts calculate the premium at 2 to 4% additional per year on top of existing Enterprise Support fees, accumulating to roughly 9% of your license value over the three-year extension window. On a significant license base, that represents a substantial sum paid for the privilege of staying still.
The Sparagus read: Extended maintenance is not a solution. It is a deferral with a price tag. It buys time, but it does not buy safety, competitiveness, or regulatory coverage. Companies using it as a long-term strategy are effectively paying more to fall further behind.
The real cost of waiting: it's not just the maintenance fees
The financial case for delaying migration looks superficially rational: avoid a large project cost now, pay a modest premium for extended support, migrate later when the market stabilises. The problem is that this calculation ignores the structural costs that compound in the background.
Consulting rates are rising, fast
With the majority of large enterprises already in migration or completed, the remaining pool of experienced SAP migration consultants is shrinking. The Silicon Partners estimates consulting rates have risen 30 to 50% in 2026-27 compared to companies that moved earlier. Skills in data migration, finance module configuration, and BTP development are particularly constrained. Companies that delay are not just paying extended maintenance fees. They are queuing for an increasingly expensive and oversubscribed resource market.
Technical debt compounds quietly
Every custom development, every workaround, every manual process built on top of ECC is a line of technical debt that will need to be assessed, adapted, or removed during migration. The longer a system runs without modernisation, the heavier that debt becomes, and the more complex and expensive the eventual transition.
Data quality deteriorates over time
According to Basis Technologies, poor data quality is the single greatest risk factor in S/4HANA migrations. Legacy ECC environments often contain decades of duplicated, incomplete, or obsolete data. When moved to an in-memory platform, these issues surface immediately, causing unreliable reporting and operational disruption at go-live. Companies that delay migration are allowing that problem to grow.
The hidden cost: scope decisions made by default
The Silicon Partners describe a concept called decision compression: the gradual narrowing of strategic options as organisations delay. Companies that plan early choose their migration approach deliberately. Companies that arrive late choose it by necessity, typically defaulting to a brownfield lift-and-shift that reproduces existing processes rather than improving them, at higher cost and with less value.
The Sparagus read: The real comparison is not "migrate now vs. migrate later at the same cost." It is "migrate now with strategic choice vs. migrate later under time pressure, with fewer consultants, at higher rates, with less room to design the outcome you actually want."
This is not just an IT project
One of the most common mistakes companies make with ERP migration is framing it as an IT project with business stakeholders to be managed. It is the opposite: a business transformation that IT delivers.
S/4HANA is not simply a newer version of ECC. It is a fundamentally different data model with real-time analytics, embedded AI capabilities, and a process architecture built for modern operations. The migration decision has implications for:
- Finance teams: new reporting structures, real-time close capabilities, changed month-end processes
- Supply chain and operations: integrated planning, predictive analytics, inventory management redesign
- HR and people management: changed workflows, new self-service capabilities, integration with SuccessFactors
- Data governance: the migration is the moment to clean, rationalise, and structure data for the next decade
According to Birchman Group's S/4HANA migration analysis, the leading cause of cost overruns is scope expansion during the project, driven by business units that weren't engaged early enough to define their requirements upfront. The migration is also the single best opportunity to stop replicating broken processes in a new system. Companies that treat it as a lift-and-shift lose most of the business value S/4HANA offers.
The Sparagus read: The companies that extract the most value from S/4HANA migration are the ones that treat it as a process redesign project that happens to involve a technology change, not the other way around. That requires finance, operations, and HR to be in the room from day one, not brought in for sign-off at the end.
RISE and GROW with SAP: the migration paths available
SAP currently offers two primary migration pathways:
- RISE with SAP is designed for existing SAP customers and large enterprises with complex, customised environments. It provides a flexible path to S/4HANA Cloud Private Edition, with SAP managing infrastructure, basis, and database. RISE accounted for 41% of S/4HANA deals in recent periods.
- GROW with SAP targets smaller and mid-sized businesses looking for a standardised, fast-track adoption of S/4HANA Cloud Public Edition. Implementation timelines can be as short as four weeks for scoped deployments. GROW captured 45% of adoption in the same period, driven largely by SMEs.
Belgian companies including Farys, SABCA, IBA, and Oleon have already completed their migrations, providing local reference points on what the transition involves in practice. SAP's Cloud ERP Suite revenue, the line driven by RISE and GROW, grew 30% year-on-year in 2025, reflecting accelerating adoption as the 2027 deadline approaches.
How to approach migration without being overwhelmed by it
What distinguishes lower-risk migrations:
- A landscape assessment completed before commitment. Understanding what you have, including custom code, integrations, and data quality, before defining scope prevents the scope expansion that drives cost overruns.
- Executive sponsorship that is real, not nominal. The projects that stall are almost always the ones where the C-suite approved the budget and then delegated entirely to IT. When the CFO and COO are actively involved in design decisions, trade-offs get resolved faster and scope doesn't drift.
- A phased approach with defined quick wins. Starting with finance and core procurement modules, proving value, and expanding in subsequent phases is more manageable than attempting a full-landscape migration in a single programme.
- Data as a first-class workstream, not an afterthought. Allocating dedicated resource to data assessment and cleansing from the start of the project is the single highest-leverage investment in reducing go-live risk.
The Sparagus read: A well-prepared migration in 2026 is significantly less risky than a pressured one in late 2027 with constrained consultants, limited options, and a deadline that doesn't move. Postponing is almost always more expensive and more risky than anticipating, when the full cost picture is properly modelled.
In short
The SAP ECC maintenance clock is running. 17,000 companies are heading toward a 2027 deadline without a completed migration. Consulting rates are rising. The talent pool is tightening. And every additional month on ECC is a month of technical debt, security risk, and missed modernisation opportunity.
The 2027 deadline is not a technology event. It's a governance decision that every board-level leader at a company running ECC should have visibility of right now. The question is not whether to migrate. It's whether to migrate on your terms, or under pressure.
For Belgian companies, the opportunity is also real: S/4HANA with embedded AI capabilities positions organisations to do more with their data than ECC ever allowed. The migration is not the end goal. It's the foundation for the next decade of operational competitiveness.
