ECC to S/4HANA Migration Statistics (2026): Adoption, Deadlines, Cost, Risk and Testing

SAP's mainstream maintenance for ECC 6.0 ends on December 31, 2027, and a large share of the installed base will still be on ECC on that date. This page collects the most recent independent numbers on how far the market has moved, what migrations cost, how often they slip, and where quality breaks down. It is written for the people who have to sign off on go-live.

Key takeaways

Where the ECC installed base stands

Gartner's count of the base is the most widely quoted. It puts the installed base at about 35,000 ECC customers. Gartner's progress figure has crept up a few points per year since 2022.

• At the end of 2024, only 39% of those 35,000 customers, or about 14,000, had moved to S/4HANA by Gartner's measure. At that rate Gartner projects about 17,000 holdouts, nearly half the base, in 2027 (Gartner via CIO, 2025).
• The definition matters. CIO reported the 39% as customers that had "migrated." The Register reported the same Q4 2024 Gartner figure as customers that had "bought or subscribed to licenses" to start their transition (The Register, November 2025). Treat it as a licensing number, not a go-live number.
• In Q2 2023, about a fifth of ECC users were live on S/4HANA in at least one component, while 33% had bought or subscribed to S/4HANA licenses (Gartner via The Register, October 2023).
• Forrester's Akshara Naik Lopez projects that more than 40% of ECC customers will still be on the legacy ERP after 2027 (CIO, 2025).
• A second Gartner estimate says more than 60% of SAP customers are still on ECC 6 on-premises with no decision yet to move. It also says four in ten of today's ECC customers will still use ECC in key business areas in 2030 (Gartner via The Register, June 2025).

Source: Gartner figures reported by The Register, October 2023 (Q2 2022, Q2 2023) and CIO, 2025 (Q4 2024). Share of ECC customers with any S/4HANA license.

User-group surveys report much higher progress than Gartner. Their samples are self-selected members, and most of them count "started" or "partly live" as progress. The figures below are not directly comparable.

Sources: Precisely/ASUG, November 2025; ASUG via CIO, May 2026; DSAG via all-about-security.de, February 2026; SAPinsider, 2026; Gartner via CIO, 2025

SAPinsider separates "deployed" from "done." Its 2026 benchmark surveyed 296 community members between December 2025 and March 2026 (SAPinsider, 2026). The gap between the two numbers below is mostly parallel running, multiple ERP instances and pilots.

Source: SAPinsider Benchmark Research: ERP Migration and Transformation 2026

Deadlines and the extended-maintenance math

• Mainstream maintenance for ECC 6.0 on enhancement packages 6 to 8 ends December 31, 2027 (Qyrus, 2026, vendor summary of SAP's support schedule). For EHP 0 to 5, mainstream maintenance has already ended (operayo, 2026).
• Extended maintenance runs to the end of 2030 for a 2% premium (The Register, November 2025). Customers that have not opted in by the end of 2027 are moved to customer-specific maintenance automatically (operayo, 2026).
• The SAP ERP, private edition, transition option can be bought from 2028 and used from 2031 to 2033. It requires a RISE contract and is not an extension of maintenance (Gambit Consulting, 2025).
• Eligibility as summarized by one consultancy: systems must be on SAP ERP, private edition on SAP HANA before December 31, 2030, be at least 2 TB, and use the Max Success plan. Customers that sign up in 2026 get a standard 20% price uplift when they switch to the option in 2031 (operayo, 2026).
• DSAG cites an SAP maintenance commitment for S/4HANA until 2040 (DSAG Annual Congress coverage, October 2026).

DSAG's 2026 Investment Report surveyed 198 member companies in Germany, Austria and Switzerland in December 2025 and January 2026 (IT-Matchmaker, 2026). Among respondents still on ECC, most plan to finish after the mainstream deadline:

Source: DSAG Investment Report 2026, via Constellation Research, February 2026 and operayo, 2026

Gartner's outlook is similar: more than a third of the base is expected to still run ECC in 2030 (Panorama Consulting, citing Gartner, 2026).

Deployment choices: on-premises, private cloud, public cloud

In SAP's home market, on-premises S/4HANA has overtaken ECC for the first time, and private cloud is growing from a small base.

Source: DSAG Investment Report 2026 (DACH, 198 respondents), via Security Storage und Channel Germany, March 2026 and all-about-security.de, February 2026

• For 2026, 42% of DSAG respondents plan high or medium investment in S/4HANA on-premises, 22% in private cloud and 6% in public cloud. 10% plan high or medium investment in ECC (DSAG, February 2026).
• Conflicting data: The 2025 DSAG report showed 33% on S/4HANA private cloud (up from 11%) and 48% using or planning to use RISE (Constellation Research, 2025). That year SAP, not DSAG, distributed the questionnaire, and the sample had more large enterprises (Constellation Research, 2026). The 2026 figure of 17% is the like-for-like comparison with 2024.
• Among SAPinsider respondents, S/4HANA Cloud usage (26%) is nearly level with traditional S/4HANA (29%) for the first time in its tracking (SAPinsider, 2026).
• Among ASUG members in 2024, 17% had RISE with SAP S/4HANA Cloud, private edition in place and 59% were planning or considering it (ASUG, 2024 S/4HANA research).
• 75% of the 200 companies in Horváth's study rely on cloud hosting (Horváth, April 2025).

SAP's own numbers: backlog and Cloud ERP Suite

SAP does not publish an ECC-to-S/4HANA conversion count. Its cloud backlog and Cloud ERP Suite revenue are the closest public proxies, because RISE contracts are counted there. Q2 2026 is the latest quarter reported as of this update.

Current cloud backlog, € billions. Source: SAP Q2 2024 results; SAP Quarterly Statement Q2 2026 (includes Q2 2025 comparative)

Cloud ERP Suite revenue, € billions. Source: SAP Q2 2024 results; SAP Quarterly Statement Q2 2026

• In Q2 2026, current cloud backlog reached €22.9 billion, up 27% (26% at constant currencies). Cloud ERP Suite revenue rose 25% (27% at constant currencies) (SAP Q2 2026 statement, SEC 6-K).
• Cloud ERP Suite made up 88% of SAP's Q2 2026 cloud revenue (Investing.com, July 2026).
• Software support revenue, which still includes ECC maintenance, fell 11% to €2.47 billion in Q1 2026 as customers converted to subscriptions (SAP Q1 2026 statement, SEC 6-K).
• Total cloud backlog stood at €63.3 billion at the end of 2024 (SAP Q4 and FY 2024 results).

Budget and cost

• Budget constraints are now the top challenge for SAP customers, cited by 61% of respondents to ASUG's 2026 Pulse survey. That is up 7 points year over year, and ASUG attributes the pressure mainly to S/4HANA projects (ASUG via CIO, May 2026).
• In ASUG's 2024 S/4HANA research, total project costs matched expectations for only 23% of respondents, down 13 points from the year before. Another 24% were unsure (ASUG, 2024).
• Panorama Consulting puts migration budgets at roughly $2 million for a contained environment and more than $1 billion for a large, heavily customized enterprise (Panorama Consulting, 2026).
• 79% of DSAG respondents said cost effectiveness strongly influences SAP investment decisions, and 70% named SAP's licensing and contract design (DSAG via heise, February 2026).
• Vendor data: in a Rimini Street survey of 455 IT and business leaders, 95% said the S/4HANA ROI case is challenging, and 83% said they do not fully understand SAP's latest migration policies and deadlines (Rimini Street, October 2025). Rimini Street sells third-party support as an alternative to migrating.
• Among SAPinsider respondents with no S/4HANA plans, 50% struggle to articulate a clear value proposition (SAPinsider, 2026).

Timelines, overruns and failure risk

Horváth's study is the most detailed independent data on S/4HANA outcomes. It surveyed 200 companies with at least €200 million in revenue and 200 employees, in the DACH region plus selected Northern and Eastern European countries, and was published in spring 2025.

Source: Horváth study via Computerwoche, March 2025; Horváth press release, March 2025

• Projects ran an average of 30% longer than planned (Horváth, 2025). More than 40% of respondents would set a higher budget from the start (Computerwoche, 2025).
• ISG's February 2026 State of SAP Migrations report surveyed more than 200 senior decision-makers. It found that nearly 60% of SAP migration projects run late or over budget (ISG as reported by Qyrus, 2026).
• Conflicting benchmark: Panorama's 2026 ERP Report found that just over a quarter of organizations went over budget (Panorama Consulting, March 2026). That report covers all ERP projects across vendors, not only SAP. Use it as a cross-vendor baseline, not as a figure for S/4HANA.
• Duration estimates vary: Panorama says most ECC migrations take 18 to 36 months (Panorama Consulting, 2026). Gartner reports clients planning for three- to seven-year programs (CIO, 2025). The gap likely reflects single-instance technical conversions compared with multi-country transformations.

Testing, data and quality

The quality findings matter most for sign-off. In Horváth's study, testing is named as a cause of plan deviations, not only a symptom.

• Horváth's respondents named these main reasons for plan deviations: scope growth, weak project management, underestimated testing and data migration phases, rework loops on concepts and processes, and slow decision-making (Horváth via WirtschaftsWoche, March 2025).
• Even after budget and schedule overruns, 65% reported strong to very strong quality deficits in the result (Horváth, 2025).
• Integration is a growing focus. 44% of 787 ASUG members surveyed in November 2024 named integration between SAP and non-SAP systems as a focus, up from 36%, and 37% named integration within SAP (ASUG Pulse 2025).
• Historical (2022): 61% of 116 UKISUG members said data management issues were slowing process automation and S/4HANA moves (UKISUG via Computer Weekly, April 2022).

The Precisely/ASUG survey (vendor-sponsored) found automation use flat while migrations accelerate. Automation use stood at 57%, down 1 point from 2024 (Enterprise Times, November 2025).

Source: Precisely and ASUG, "Transforming SAP Processes Through Automation: 2026 Trends and Challenges," via Enterprise Times, November 2025 (vendor data)

Vendor-reported example: SAP said customer Dexco eliminated about 97% of its legacy customizations using SAP's toolchain (SAP Q2 2026 presentation via Investing.com). That is one customer, not a benchmark, but it shows how much regression scope changes in a clean-core redesign.

People, skills and change

• Organizational resistance remains a core obstacle for 37% of SAP customers in the Precisely/ASUG survey (Enterprise Times, 2025).
• Horváth's study lead says many programs underestimate complexity and resource needs and overestimate their own organizational capability. He calls this mismatch the root of the gap between plan and result (Computerwoche, 2025).
• 36% of 787 ASUG members named standardizing business processes as a priority (ASUG Pulse 2025).
• Historical (2022): 92% of UKISUG organizations yet to move were concerned that a lack of skills would slow their migration, up from 71% in 2021. 32% rated their partner's training as poor or very poor (UKISUG via CIO, 2022). We did not find a newer independent skills survey with comparable questions.

AI and the migration agenda

In 2026, AI overtook the 2027 deadline as the most-cited external driver of ERP strategy among SAPinsider respondents.

Source: SAPinsider, "5 Hard Truths About the 2026 SAP ERP Migration Landscape," 2026

Execution is lagging behind intent. ASUG's February 2026 AI survey of 142 members, run with Microsoft and Intel, shows most organizations still at the pilot or learning stage:

Source: ASUG via CIO, May 2026

• The top enablers ASUG members named for AI adoption were clear governance and frameworks (40%), alignment with business processes (39%) and clear use cases (39%) (ASUG, July 2026).
• In DACH, 43% of DSAG respondents invest in AI technologies generally, but only 3% invest in SAP Business AI (DSAG Investment Report 2026 via Change Orchestration).
• 53% of UKISUG respondents said access to SAP's AI offerings would influence their future SAP deployment. Only 3% said they were extremely familiar with Joule (UKISUG, December 2024).

Outlook: how much of the base will move, and when

Fewer customers are deferring. The share of ASUG members planning to wait more than two years has fallen steadily:

Source: ASUG via CIO, May 2026 (2023, 2025); ASUG, 2024 (2024)

• In 2024, 30% of ASUG respondents expected to go live in the next 6 to 24 months, and 1% had no plans to move (ASUG, 2024).
• SAPinsider's 2025 research found 34% had completed their move and another 41% planned to move before the end of 2027 (SAPinsider, 2026). The 2026 benchmark still shows 34% complete, which suggests many of those 2027 plans have not yet converted.
• ASUG's September 2026 S/4HANA research gives a headline of 68% community adoption, with value realized in 6.9 months (ASUG Talks, September 2026). The full definitions were not public when we checked, so do not compare it directly with the 56% figure above.
• Historical, vendor model (2023): Basis Technologies projected that 57% of ECC customers would finish by the end of 2027 and 80% by 2030 (Basis Technologies, 2023). That is more optimistic than Gartner's projection of about 17,000 holdouts.

What this means for your sign-off

• Plan test windows for the overrun you will probably have. Projects ran an average of 30% over schedule, and only 8% of completed programs finished on time (Horváth, 2025). If testing sits at the end of the plan, it takes up the slippage. Protect SIT, regression and UAT windows explicitly in the phase-by-phase migration test plan.
• Treat data migration as a test stream. "Underestimated testing and data migration phases" is one of the named reasons for deviation, and 65% report quality deficits after go-live. Budget for repeated data loads, reconciliation and masked copies. Our S/4HANA test data guide covers the options.
• Make the 2027, 2030 and 2033 decision explicit. 49% of DSAG respondents plan to finish only by 2030 under paid extended maintenance. Your go/no-go criteria should not be driven by a date the business has already decided to miss. See what 2027, 2030 and 2033 really mean.
• Define "done" as decommissioned, not deployed. SAPinsider's gap between 55% deployed and 34% fully switched means long parallel runs and dual regression scope. Include legacy shutdown criteria in exit criteria and on the UAT sign-off form in our template library.
• Do not assume automation is in place. Automation use was flat at 57% in the Precisely/ASUG data while migrations accelerated. If your regression suite is manual, it will not keep pace after go-live.
• Govern AI before you scale it. Only 10% of ASUG members have AI at enterprise scale, and governance is the most-cited enabler (40%). Approve AI-generated test assets through a review gate before they count toward coverage.

Frequently asked questions

How many SAP customers are still on ECC?

Gartner estimates about 35,000 ECC customers. Only 39% had licensed S/4HANA by the end of 2024, and Gartner projects about 17,000 will still be on ECC in 2027 (Gartner via CIO, 2025).

What percentage of S/4HANA migrations go over budget?

In Horváth's 2025 study of 200 companies, 40% overran their budget strongly and another 25% very strongly (Computerwoche, 2025). ISG's 2026 report puts the share running late or over budget at nearly 60% (ISG via Qyrus, 2026).

How long does an ECC to S/4HANA migration take?

Panorama Consulting says most take 18 to 36 months (Panorama, 2026). Gartner reports clients planning three- to seven-year programs (CIO, 2025). Horváth found projects run an average of 30% longer than planned (Horváth, 2025).

What does extended maintenance for ECC cost?

Extended maintenance to the end of 2030 carries a 2% premium on maintenance fees (The Register, 2025). The private edition transition option covers 2031 to 2033. One consultancy reports a 20% uplift for customers that sign up in 2026 (operayo, 2026).

How many companies have actually finished their S/4HANA migration?

In SAPinsider's 2026 benchmark of 296 respondents, 55% have deployed S/4HANA but only 34% have fully completed the transition (SAPinsider, 2026).

Is AI changing why companies migrate?

Yes. 43% of SAPinsider respondents cite SAP's AI announcements as the main external factor shaping ERP strategy, ahead of the 2027 deadline at 39% (SAPinsider, 2026). Only 10% of ASUG members have reached enterprise-scale AI rollout (ASUG via CIO, 2026).

Sources

1. Nearly half of SAP ECC customers may stick with legacy ERP beyond 2027, CIO (Gartner and Forrester data), 2025
2. SAP barely moving needle to migrate users off ECC before support ends, The Register (Gartner data), October 11, 2023
3. SAP ECC 6.0 lives to fight another decade under Rimini Street, The Register (Gartner data), June 20, 2025
4. Kingfisher and SAP ECC, The Register (Gartner data), November 19, 2025
5. Benchmark Research: ERP Migration and Transformation 2026, SAPinsider, 2026
6. 2026 ERP Migration Realities: Cloud, AI, and the Looming Transition Bottleneck, SAPinsider, 2026
7. 5 Hard Truths About the 2026 SAP ERP Migration Landscape, SAPinsider, 2026
8. Abacus Maps the SAP ECC to S/4HANA Decision, SAPinsider, 2026
9. SAP customers say migration is eating their budgets, CIO (ASUG 2026 Pulse data), May 2026
10. The State of SAP S/4HANA Adoption, ASUG, 2024
11. ASUG Pulse of the SAP Customer Research 2025, ASUG, 2025
12. Navigating AI in SAP Landscapes, ASUG, July 2026
13. ASUG 2026 SAP S/4HANA Research, ASUG Talks, September 6, 2026
14. New Research Reveals SAP S/4HANA Migration Momentum, Precisely with ASUG (vendor), November 2025
15. Precisely and ASUG see S/4HANA migrations surge as automation stalls, Enterprise Times, November 6, 2025
16. DSAG Investment Report 2026, DSAG, February 2026
17. DSAG: SAP customer spending selective, AI drags, Constellation Research, February 2026
18. SAP S/4HANA Cloud strategy makes headway, says DSAG, Constellation Research, 2025
19. SAP users focus more on economic efficiency, heise, February 2026
20. DSAG-Investitionsreport 2026: SAP bleibt gefragt, all-about-security.de, February 26, 2026
21. SAP Investments 2026: Targeted Spending, Security Storage und Channel Germany, March 2026
22. DSAG: Mehr Budget, mehr S/4HANA, IT-Matchmaker, 2026
23. DSAG Investment Report 2026: Three percent SAP AI versus 43 percent total AI, Change Orchestration, 2026
24. DSAG-Jahreskongress 2026, jeko, October 2026
25. Study shows: SAP S/4HANA transformations rarely go as planned, Horváth, April 10, 2025
26. SAP-Anwender kämpfen mit S/4HANA-Migration, Computerwoche, March 2025
27. 60 Prozent aller Projekte zur Einführung von SAP S/4Hana reißen Budget und Zeitplan, WirtschaftsWoche, March 2025
28. Why SAP S/4HANA migrations miss their deadline, Qyrus (ISG data; vendor blog), 2026
29. 18 Months to the SAP ECC Cliff, Panorama Consulting, 2026
30. Panorama Releases 2026 ERP Report, Panorama Consulting, March 4, 2026
31. Quarterly Statement Q2 2026, SAP, July 2026
32. Quarterly Statement Q1 2026 (Form 6-K), SAP, April 2026
33. SAP Announces Q2 2024 Results, SAP, July 2024
34. SAP Announces Q4 and FY 2024 Results, SAP, January 2025
35. SAP Q2 2026 slides, Investing.com, July 23, 2026
36. Global Study Finds Most SAP Customers Favor Multi-Vendor Composable ERP, Rimini Street (vendor), October 16, 2025
37. SAP ECC end of maintenance 2027: what ends and what applies after, operayo, 2026
38. SAP ERP, Private Edition, Transition Option, Gambit Consulting, 2025
39. SAP ECC End of Life 2027, Qyrus (vendor blog), 2026
40. Almost three quarters of SAP users in the UK and Ireland think enterprise AI will benefit their organisation, UKISUG, December 2024
41. SAP user groups see pick-up in migration to S/4HANA, CIO (UKISUG data), 2022 (historical)
42. UKISUG: Big majority of SAP users beset by data problems, Computer Weekly, April 2022 (historical)
43. The True State of S/4HANA, Basis Technologies (vendor model), 2023 (historical)

Last updated: October 10, 2026. Statistics are refreshed as new research is published.