An implementation quote with the total underlined in red looks impressive, right up until you work out what the same system will cost in its fifth year of use. Hidden ERP costs do not arise because a vendor deliberately conceals something, but because an implementation quote, by its very nature, describes the start of a project, not the five years of its life. The owner of a manufacturing company employing 10-50 people who compares three quotes on the implementation price alone is, in practice, comparing three different, incomplete bills. In this article we show the TCO of an ERP system year by year, where the licence fees and ERP maintenance costs hide, and how to compare vendor quotes on the full five-year cost rather than on the figure on the first page of the PDF.
What ERP TCO is, and why the quote does not show it
TCO, the total cost of ownership of a system, is the sum of everything a company will pay for its ERP over a given time horizon: licences, implementation, data migration, training, support, updates, modifications and the additional users who join as the team grows. The implementation quote you receive from a vendor describes, in effect, only the first of these items in full, namely the implementation, plus the licence in its form on the day the contract is signed. It does not describe what will happen to the cost in the second, third or fifth year, because at that moment nobody simply knows yet: the team may grow, regulations may change, the production process may require a new module.
This is not the vendor's fault. It is simply a different document, answering a different question. The problem begins when a company treats the implementation price as the entire purchasing decision, rather than as the first instalment of five years of payments.
Year by year: how ERP maintenance cost grows
The cost of an ERP system is not flat over time. In the first year the one-off items dominate; in the following years an ever larger share of the budget is taken over by recurring items that do not appear in the implementation quote at all, because they concern a future that cannot yet be precisely calculated at the moment the contract is signed.
| Year | What dominates the cost | Nature of the cost |
|---|---|---|
| Year 1 | Licences for the launch, implementation and configuration of modules, data migration from Excel or an old system, team training | Mostly one-off; this is precisely the figure shown in the quote |
| Year 2 | Licence renewal, the first technical support after the warranty period, the first system updates | Recurring; the bill the quote did not show begins here |
| Year 3 | More users as the team grows, minor process modifications that turned out to be a poor fit at launch | Recurring plus ad hoc |
| Year 4 | Integrations with new systems or sales channels, adjustments to regulatory changes (e.g. KSeF) | Ad hoc, usually not planned in the initial budget |
| Year 5 | A larger expansion of the system with a process the company did not have in year 1 (e.g. full MRP on entering a new production line) | One-off, but comparable in scale to part of the year 1 implementation |
One pattern is visible here: the licence is usually 10 to 50% of the whole budget, according to data published by ERP vendors such as humansoft.pl, and the rest is work that has to be done in each of those five years, not only in the first. Anyone who measures the cost of an ERP purely by the price in the implementation quote usually sees one fifth or one third of the full five-year bill.
Four hidden ERP costs that rarely reach the first quote
Licence fees for new users
A manufacturing company that has 20 seats today may have 30 in three years. In models charged per user, every new seat is a new line in the budget that was not in the original quote, because the quote was calculated for the team on the day the contract was signed, not for the team in year 3.
Updates and regulatory compliance
An ERP system has to keep pace with changing law, not only with a growing team. The obligation to receive invoices in KSeF takes effect on 1 February 2026 for all taxpayers, and the obligation to issue invoices in KSeF covers practically all of B2B from 1 April 2026, with the exception of the smallest companies (gross sales up to 10,000 PLN per month), for which the deadline has been moved to 1 January 2027. Every such change in the regulations is a system update that had to be planned and paid for, regardless of whether the implementation quote from two years earlier mentioned it at all.
Technical support after the warranty period
The first weeks after the production go-live of a system are usually covered by support included in the implementation price. Year 2 and the years that follow are already a separate contract and a separate invoice, and it is that invoice which accounts for most of the ERP maintenance fees over the long run, far more often than the licence subscription itself.
Modifications and process expansion
A manufacturing company rarely rolls out everything it will need in five years all at once. A new production line, a new sales channel, integration with an external warehouse: each of these changes is a separate small project on an already running system, not something that fit into the year 1 implementation budget.
How to compare vendor quotes on TCO, not on implementation price
Two quotes with the same figure on the first page can lead to completely different costs in the fifth year. Before you sign the contract, it is worth asking the vendor directly about five things that no standard quote shows on its own:
- Exactly how the licence is charged when further users are added in later years, and whether the rate is guaranteed or may change.
- What exactly the technical support included in the implementation price covers, and what costs extra once that period ends.
- Whether system updates, including those forced by regulatory changes such as KSeF, are included in the subscription, or constitute a separate, individually priced project every time.
- How much a typical post-implementation process modification cost at this vendor, for another client of a similar scale, in the second or third year of the cooperation.
- Whether the licensing model charges per user with access to all modules, or per module separately, because the second of these options means that every new process added to the system generates a new, fixed licence fee, on top of the cost of the implementation work itself.
A practical rule of thumb when planning a multi-year budget: count on 1% to 3% of the company's annual revenue for the entire digitalisation project per year, not as a one-off, until the system settles into a phase of pure maintenance without major expansions. A quote that looks far cheaper than this rule would lead you to expect usually does not yet show the costs from year 2 onwards.
How we calculate TCO in practice
We have worked with Odoo since 2011, for clients in three countries, Poland, Germany and Belgium. Our first implementation began with a demo shown to the client the day after the first conversation, and we launched a working system two weeks later. That company was later acquired by a listed German group, and the same system core runs there to this day, precisely because the cost of maintenance and expansion was calculated from the outset, not added after the fact.
A licence charged per user, with access to all applications, has one practical advantage in the TCO calculation: adding a warehouse, manufacturing or CRM to seats that are already paid for does not generate a new fixed licence fee, only the cost of the implementation work on that module itself. Over a five-year horizon this is often the single largest difference between two quotes that looked almost identical at the start. You will find more comparisons of licensing models and the costs of ERP systems available on the Polish market on our blog.
Frequently asked questions
How does ERP TCO differ from the implementation price?
The implementation price is a one-off cost from year 1: launch licences, module configuration, data migration and training. TCO is the sum of that cost plus all the recurring and ad hoc costs of the following four years: renewed licences, support, updates, new users and process modifications. Comparing quotes on the implementation price alone usually shows less than half of the full five-year bill.
What percentage of an ERP budget do licence fees make up over the long run?
According to market data, published among others by humansoft.pl, the licence is usually 10 to 50% of the whole project budget, depending on the vendor's model. Over a five-year horizon this proportion shifts in favour of maintenance, support and expansion costs, because it is those, not the licence itself, that grow the most with each further year of running the system.
Does a cheaper implementation quote mean a lower TCO?
Not necessarily. A cheaper quote at the start may result from a narrower implementation scope, from a licensing model that is cheap on entry and grows more expensive with every additional module, or from leaving support and updates for later years out of the pricing. The comparison only makes sense once both quotes are spread over the same five years and the same cost components.
How do KSeF changes affect ERP maintenance cost?
The obligation to receive invoices in KSeF takes effect on 1 February 2026 for all taxpayers, and the obligation to issue invoices in KSeF covers practically all of B2B from 1 April 2026, with the exception of the smallest companies, for which the deadline has been moved to 1 January 2027. For a company using an ERP this means a system update on a specific date imposed by the regulations, a cost that was rarely included in an implementation quote signed several years earlier.
Before you compare the next implementation quote on the price on the first page alone, check how much your company will really pay over five years. The Digital Growth Diagnosis is an audit of 39 KPIs across 7 dimensions that shows where a company is losing money today and lets you calculate the full TCO of an ERP system before you sign a contract for just the first year.