Go-live is behind you, the project is closed, the project team has been disbanded. And yet the invoices keep arriving, year after year, for amounts nobody really budgeted. ERP run cost is the most underestimated part of TCO: it is discreet, recurring, and spread across several budget lines and several owners.
This article offers an honest estimate: the 7 line items of annual run cost, the variables that move each one, ranges by company profile (with sourced data clearly separated from field estimates you should validate), the classic cost drifts, 5 optimization levers and a budget template to copy. It complements our 5-year TCO comparison, which focuses on vendor selection, with a year-by-year operating view.
Why Run Is the Least Budgeted Part of TCO
During the project, everything is visible: a budget, a sponsor, a schedule, a steering committee. After go-live, spending scatters: the subscription sits with Procurement, support with IT, hosting in a general cloud envelope, enhancements in business-unit budgets. No line is called “ERP” and nobody sees the total.
Three mechanisms explain this blind spot:
- The attention shift. The steering committee stops when the project does. Nobody challenges the contracts anymore.
- Recurring by nature. A cost that renews automatically is no longer decided. It is endured.
- Silent indexation. Price increases apply without anyone deciding anything. According to a Gartner analyst quoted by The Register (September 2025), SaaS vendors raised prices “between 9 and 25% this year”, while enterprise IT budgets grow 2.8% a year according to Gartner customer surveys.
The result: the run budget mechanically drifts faster than the envelope that funds it. To frame that envelope within the annual cycle, see also our 2027 ERP budget guide.
The 7 Line Items of ERP Run Cost
1. Licenses and Subscriptions
This is the most visible item. In SaaS, it takes the form of a subscription per user, per module or per transaction volume. On-premise, perpetual licenses are already paid for: the item shrinks to additional licenses (new users, new modules).
Cost drivers:
- user type (full, limited, self-service): the mix changes the bill significantly;
- modules enabled but barely used;
- contractual indexation (index, cap or open-ended increase);
- volume tiers (transactions, legal entities, storage).
2. Vendor Maintenance (On-Premise)
On-premise, maintenance is calculated as a percentage of license value. The best-known public benchmarks come from SAP: the Enterprise Support program was set at 22% of license fees, versus 17% for the previous program (InfoWorld, 2009). These percentages remain the market reference for large vendors, but they are dated: check them against your own contract, as they vary by vendor, support tier and what you negotiated.
In SaaS, this item disappears as such: support is included in the subscription. It is one of the structural differences between the two models (see below).
Cost drivers: calculation base (list price or negotiated price), support tier, indexation clauses, scope of licenses actually covered.
3. Integrator Support and Application Maintenance
Application support (application maintenance outsourcing) covers bug fixes, key-user assistance, updates and interface monitoring. It is billed as a fixed fee, an hours bank or on demand. Our ERP maintenance contract guide details the service levels and clauses to watch.
Cost drivers: service level (business hours or 24/7), number of interfaces, volume of customizations, quality of inherited documentation, integrator staff turnover.
4. Infrastructure and Hosting
In SaaS, infrastructure is included, but extra environments (test, training, pre-production), additional storage and extended backups may be billed separately. On-premise or in a private cloud, this item covers servers or instances, databases, backup, monitoring, security and operations.
Cloud is generally poorly managed: according to Flexera’s State of the Cloud 2025 report, 84% of organizations struggle to manage cloud spend, and cloud budgets already exceed their limits by 17%.
Cost drivers: number of environments, instance sizing, off-hours shutdown policy, data volume, continuity requirements (disaster recovery).
5. Enhancements and Minor Projects
A living ERP evolves: new reports, new workflows, a new entity, a new warehouse, adaptation to a regulation. This item is the one most often forgotten in the run budget, even though it is almost certain. Regulatory reforms (e-invoicing, sustainability reporting) are recurring drivers.
Cost drivers: customization debt, request governance (who arbitrates?), whether the vendor’s roadmap covers the need as standard.
6. Internal Team (Competence Center)
This is the most underestimated item because it appears on no external invoice. It includes the application owner, key users, functional and technical administrators, and the business time spent on testing and requests. An internal team that is too small is later paid for through total dependence on the integrator and slow turnaround. See our article on the ERP center of excellence for sizing.
Cost drivers: size and complexity of scope, number of sites, key-user maturity, share of business time that is unbilled but very real.
7. Ongoing Training and Compliance
New hires, version changes, new features, regulatory updates: training doesn’t stop at go-live. Add compliance (license audits, access rights reviews, recovery tests, security requirements) and the cost of external audits.
Cost drivers: user turnover, frequency of version upgrades, sector regulatory exposure, vendor audits.
Ranges by Profile: What Is Sourced, What Is Estimated
Let’s be clear: there is no reliable, universal public benchmark for ERP run cost. The figures sold by consultancies depend on scope, sector and method. So here is what we can state, and what we present as a field estimate to validate against your own context.
Sourced data:
- on-premise vendor maintenance: 22% or 17% of license value at SAP depending on the program (InfoWorld, 2009);
- SaaS price increases: 9 to 25% observed in 2025 by Gartner (The Register, 2025).
Field estimates (not publicly sourced, to validate against your contracts):
| Profile | Indicative run breakdown | Annual order of magnitude (estimate) |
|---|---|---|
| SMB (under 100 users) | Subscription dominant, occasional integrator support, little infrastructure | 15 to 25% of the initial project cost |
| Mid-market (100 to 500 users) | Subscription or maintenance, application support, dedicated internal team | 18 to 30% of the initial project cost |
| Group (multi-entity) | Large internal team, continuous enhancements, compliance | 20 to 35% of the initial project cost |
These ranges are framing benchmarks, not promises. The best indicator remains your own history: add up the 7 items over the last 12 months, and that is your real baseline.
Two cautions when reading them:
- expressing run as a percentage of the initial project penalizes projects that were negotiated very well (a high ratio on a low starting cost);
- cost per user is more meaningful in SaaS, but it hides the internal team item and enhancements.
SaaS vs On-Premise: What Changes in the Structure of Run
| Item | SaaS | On-premise |
|---|---|---|
| Licenses / subscription | Recurring, main item | Perpetual, already paid |
| Vendor maintenance | Included in the subscription | Annual percentage of licenses |
| Infrastructure | Included (except extra environments and storage) | Your responsibility |
| Updates | Imposed by the vendor, testing required | Scheduled by you, costly |
| Indexation | Renewal increases | Maintenance indexation |
| Internal team | Lighter on infrastructure, same on functional | Infrastructure and database skills to retain |
SaaS doesn’t remove run, it shifts its structure: less infrastructure and maintenance, but a subscription whose price is renegotiated every year. The real risk becomes the renewal. On this point, see our guide on negotiating SaaS ERP renewals (in French) and the 5-year TCO comparison.
5 Classic Mistakes in Run Cost
Each mistake follows the same pattern: the trap, its consequence, the countermeasure.
1. Letting Indexation Run Without a Cap
- Trap: an open indexation clause, never reviewed.
- Consequence: increases compound. Gartner reports SaaS increases of 9 to 25% in 2025 (The Register), far above IT budgets (+2.8% a year): the gap widens every year.
- Countermeasure: negotiate a cap or a contractual index, and calculate the cumulative effect over five years before signing.
2. Paying for Shelfware
- Trap: licenses or modules purchased but unused, renewed by default.
- Consequence: a recurring cost with no value. Usage audits regularly reveal inactive accounts and undeployed modules (field observation, not quantified here for lack of a public ERP source).
- Countermeasure: an annual usage audit before each renewal. See the ERP license audit (in French) or our SAP, Oracle and Microsoft license audit guide.
3. Forgetting Environments
- Trap: a test or training environment created for the project stays on for years.
- Consequence: idle instances keep being billed, in a context where 84% of organizations struggle to manage cloud spend (Flexera, 2025).
- Countermeasure: an inventory of environments with an owner, and a rule for off-hours shutdown or deletion at expiry.
4. Accumulating Customizations
- Trap: each custom development looks cheap to build.
- Consequence: recurring costs for testing at every version upgrade, documentation and scarce skills, which inflate maintenance and enhancements.
- Countermeasure: go back to standard when the vendor covers the need, and require a maintenance cost estimate before any development.
5. Auto-Renewing Contracts
- Trap: support, maintenance and hosting renewed without review.
- Consequence: lost renegotiations and scopes that no longer match actual usage.
- Countermeasure: a calendar of expiry dates, with discussions opened 6 to 9 months before term.
5 Optimization Levers and Expected Gains
Gains depend on your starting point. We quantify them only where a source exists; otherwise we describe the mechanism.
- License rightsizing. Reassign or remove inactive accounts, move occasional users to limited licenses. Gain: direct on item 1, measurable after a usage audit.
- Proactive renegotiation. Open discussions 6 to 9 months before expiry, with credible alternatives. Gain: limit indexation, obtain a cap or a multi-year commitment.
- Environment rationalization. Shut down off-hours, delete unnecessary instances, retire project environments. Gain: a reduction of item 4, all the larger where cloud governance was absent.
- Reducing customization debt. Return to standard when the vendor now covers the need. Gain: lower testing and maintenance costs, and less risk during version upgrades.
- FinOps governance and single ownership. One owner of the run budget, a quarterly dashboard, a review committee. Gain: this is the lever that makes the other four durable. Our guide to optimizing ERP costs after go-live details how to set it up.
Reading Example: A Mid-Market Run, Hypothetical Illustration
To make the breakdown concrete, take a fictional mid-market company with 200 users, SaaS ERP, and an initial project of €1.5M. The amounts below are purely illustrative: they come from no study and serve only to show how to read a run budget.
- Subscription: the dominant item, often more than half the total.
- Integrator support / maintenance: a mid-sized item, heavily dependent on the number of interfaces.
- Enhancements: an annual envelope of the same order as maintenance, sometimes higher in a year with a regulatory reform.
- Internal team: two to four full-time people, invisible in invoices but often as heavy as the subscription.
- Infrastructure, training and compliance: individually smaller items, but they add up.
Three lessons emerge, whatever the profile:
- The real total is almost always higher than the sum of invoices. As long as internal time isn’t valued, the run budget looks artificially low, and the SaaS vs on-premise comparison is skewed.
- The items are not independent. Shrinking the internal team increases maintenance; accumulating customizations increases maintenance, enhancements and training; an undersized subscription drives up additional licenses.
- Variability comes from decisions, not from the market. Two companies with the same ERP and the same number of users can have very different run costs, depending on their request governance, their discipline on environments and the quality of their negotiation.
To move from illustration to your reality, collect the invoices of the last 12 months, value internal time (FTEs multiplied by fully loaded cost) and classify each line into one of the 7 items. The lines you can’t classify are generally the ones to examine first.
Run Budget Template: A Table to Copy
This table is the basis of a run budget the CFO can read. Fill it in with your actual contracts and assign an owner to each line.
| Item | Calculation basis | Indexation | Owner |
|---|---|---|---|
| Licenses / subscriptions | No. of users by type x contractual rate | Contractual index or cap | CIO + Procurement |
| Vendor maintenance | % of license value | Maintenance contract clause | CIO |
| Integrator support / maintenance | Fixed fee or hours bank | Annual contract revision | Application owner |
| Infrastructure / hosting | Instances, storage, environments | Cloud provider pricing | CIO / Infrastructure |
| Enhancements and minor projects | Annual envelope, arbitrated by a committee | None, revised annually | Application owner + business |
| Internal team | FTEs x fully loaded cost | Salary policy | HR + CIO |
| Training and compliance | No. of new users, audits, certifications | Provider pricing | CIO + business |
Add three tracking lines: an annual total, a run / initial project cost ratio and a cost per active user. These three indicators are enough to spot a drift from one year to the next.
Going Further
To compare your run budget against a structured grid, download our ERP evaluation grid: 30 criteria scored out of 100 points. You can also contact us for a benchmark of your run cost across your 7 line items.
