How Much Does a Custom ERP System Cost in 2026?

A quote with one final figure is not enough for comparison. One provider may include ready-made modules and limited customisation, while another may develop new logic, API connections, mobile access and specialised reports. The two quotes can look different even when they use the same terms, such as “inventory”, “sales” or “automation”.

What budget should you plan for an ERP system?

The following table is an indication of scope, not a promise of a specific quote. Within each range, it matters exactly what the system will do, which data will be transferred and which external services will be connected.

The price increases when the system has to follow many different rules for separate roles, handle exceptions or exchange data with several external systems. The quality of the legacy data, the number of migration sources and the training required for the team also matter.

Which parts of an ERP project increase the cost?

Processes, roles and exceptions

A system for the manager alone is simpler than one in which the salesperson creates a quote, the warehouse employee reserves the goods, the manager approves the discount, the accountant issues the invoice and the customer tracks their status in a portal.

So do not describe only the modules. Describe the decisions people make every day. Who approves a special price? When are goods reserved? What happens in the event of a partial delivery, return or overdue payment? These rules define the scope more accurately than a list of menus.

Inventory, sales and production

The basic entities are usually customers, suppliers, products, quotes, orders, inventory movements, invoices, payments and reports. The project becomes more complex when it involves serial numbers, batches, expiry dates, different units of measurement, commissions, contracts and subscriptions.

For production, recipes, operations, costing, batches and inventory control need to be defined. A service business may need job cards, schedules, photos, signatures and site history. These details are what turn the general requirement “we want an ERP” into a specific scope for custom ERP system development.

Integrations and API connections

Connecting an online store, courier, payment provider, accounting software, bank or telephony system is not simply a matter of enabling a ready-made connector. You need to define which system is the source of truth for the product, customer, inventory, order and payment.

A good integration also handles problems: a dropped connection, a duplicate order, an out-of-stock product or a different status from the courier. Logs, notifications and the ability to resend data are essential. When multiple external systems are involved, ask for a separate description of the API integrations, not just a single line in the quote.

Data migration

Migrating data from Excel, an old ERP system or accounting software often looks like a small task-until you open the actual files. The same customer may appear under several names, products may use different units of measure, and old documents may have no clear connection to one another.

The cost depends on the number of data sources, cleaning, transformation and validation. A good practice is to run a test migration with real but anonymized data. The old archive should remain accessible until you have verified the new reports and balances.

Mobile access

Mobile access may mean a responsive web system on a phone or a separate app. For warehouse operations, a phone with a barcode scanner may sometimes be enough. A field technician may need photos, geolocation, signatures, offline functionality and synchronization once the connection is restored.

Do not pay for a separate app if your team works only from the office. If, however, work orders are completed at the customer’s site, the mobile module is part of the core process, not an optional extra.

What should an ERP proposal include?

The proposal should break the project down into clear stages. For each stage, ask for the deliverable, acceptance criteria and a list of what is not included. This will allow you to compare the actual scope, not just the final price.

1. 01
   Describe one process from start to finish

   Choose the process that creates the most manual work-for example, from enquiry to delivery. Record who accepts the request, who checks availability, who approves it, when the order is placed with the supplier and when the invoice is issued.

2. 02
   List the roles and exceptions

   Describe what the sales representative, warehouse employee, manager, accountant and customer see. Include partial deliveries, refusals, returns, overdue payments and other situations that do not follow the standard path.

3. 03
   Prepare real examples

   Provide anonymized Excel files, quotations, invoices, stock lists and reports. Mark the required fields, historical data and documents that must be retained.

4. 04
   Separate the first version from later stages

   The first version should solve the most costly problem. Dashboards, AI features, a customer portal or a mobile app can wait until a later stage if they are not needed at launch.

5. 05
   Ask for a comparable proposal

   Analysis, prototyping, development, testing, migration, training, implementation, hosting, third-party licences, support, and ownership of the code and data should all be described separately.

Which costs are often left out of the price?

Hosting and backups may be separate services. The same applies to SMS, telephony, payment providers, courier services, maps, external AI services and licensed APIs. Their cost is specified in the proposal based on the particular provider and usage volume.

Check whether migration, training and implementation are included. The system may work technically, but the project is not complete if people continue maintaining parallel spreadsheets and sending orders by email.

Support usually includes monitoring, backups, updates, bug fixes and a specified amount of time for changes. For support of the completed system, the guideline price is €100-€350 per month. What the service includes depends on the working hours, response time and agreed service level.

Is a ready-made ERP or a custom system the more sensible choice?

Ready-made business software is suitable when processes are standard: contacts, tasks, quotations, invoices, inventory and basic reports. It usually gets you up and running faster and means you do not have to maintain custom logic for every action. See business software if the problem is scattered information and a lack of an overall view.

A custom ERP makes sense when a ready-made product forces the team to work around its rules with Excel, manual emails and duplicate data entry. It also makes sense when a specific process is a competitive advantage that you do not want to change just to fit ready-made software.

Sometimes you do not need a new ERP. If you already have inventory and accounting systems but salespeople are losing enquiries, a CRM connected to inventory levels may solve the problem. If employees only copy data between two programs, automation or an API integration may be more sensible than a completely new system.

How do you compare two ERP proposals?

Compare the outcome, not the number of features. “Inventory module” is not a sufficient description. It should be clear whether it includes reservations, transfers, stocktaking, barcodes, batches, serial numbers and a change history.

Check who is responsible for analysis, UX, prototyping, testing, migration and training. Ask how each stage is accepted, how a requirement can be changed after approval and what you receive after the warranty period.

Compare the assumptions as well. One proposal may assume that clean data is ready for import, while another may include data cleaning and a test migration. One may use a ready-made module, while the other develops new logic. Without these clarifications, the lower price often means a narrower scope.

What should you do before asking for a specific price?

Start with the most costly manual task, not with a desire for “end-to-end digitalisation”. Describe where enquiries get lost, what errors lead to returns, which reports are prepared manually and which data is entered more than once.

Then gather the documents, roles and exceptions in a short file. This will enable the provider to ask the right questions and price the project based on its scope. If the process is unclear, the first step may be an analysis, with its price specified in the proposal.

Frequently asked questions

The answers below are useful for an initial budget, but they do not replace a description of the processes and a review of the actual data.