Best Custom Software Development Companies in Belgium for 2027

There is no single best software company for every Flemish or Belgian organisation, only a best fit per project. For one bounded system built around Odoo, Teamleader, Exact Online or structured Peppol invoices, delivered at a fixed price with the code handed over, our pick for 2027 is Crux Digits. For multi-year programmes, managed services or an estate that runs on Odoo itself, eight other Belgian firms below fit better.

This list is written for the IT manager, IT director, CIO or informatiemanager at a Belgian organisation of 250 to 5,000 FTE that already has an ICT partner and needs software built next to it. Disclosure: Crux Digits publishes this list and is listed first. We say why, and who the others are better for.

How did we choose the software companies on this list?

We applied five criteria, checked on each firm's own website on 29 October 2026, and left out every firm we could not verify.

• It builds custom software itself and has an office in Belgium named on its own site. Crux Digits is the exception and says so: we work from the Utrecht region, with discovery and go-live on site in Flanders.
• Its positioning is public and checkable: what it builds, where and for whom, in its own words.
• It fits a 250 to 5,000 FTE buyer that has an existing IT organisation, not only start-ups or consumer brands.
• We can name a buyer for whom it is the better choice than Crux Digits.
• Nobody paid to be here. There are no affiliate links, paid placements or reciprocal listings on this page.

The list is not a ranking beyond our own pick. Crux Digits is first because we publish the list and say so; the entries after ours are in alphabetical order. We did not invent ratings, review counts or client names, and we quote prices only where a firm publishes them. If you are buying in the Netherlands rather than Belgium, our overview of custom software development companies in the Netherlands covers that market.

What changed for Belgian software buyers between 2026 and 2027?

Three things changed the brief: Peppol e-invoicing became mandatory on 1 January 2026, its tolerance periods have ended, and Odoo is retiring its old APIs.

Since 1 January 2026, every Belgian enterprise liable to VAT must exchange structured electronic invoices with other Belgian enterprises over the Peppol network. A PDF sent by email or through a platform no longer counts, according to the FPS Finance e-invoicing site. The general tolerance period covered the first three months of 2026, and a narrower tolerance for self-billing ran until 30 June 2026. The authority has confirmed both have ended, so a 2027 project has no grace period to plan around. The same site already publishes a FAQ on the future e-reporting obligation, the next stage, in which e-invoices are reported to the administration. Ask any supplier how its design leaves room for that.

Odoo 19 introduced an External JSON-2 API, and Odoo's own documentation states that the XML-RPC and JSON-RPC endpoints are scheduled for removal in Odoo Online 21.1 (winter 2027) and Odoo 22 (fall 2028). Any integration written today against /xmlrpc or /jsonrpc therefore has a known expiry date. On Odoo Online that date falls inside the 2027 budget year.

For a buyer, this moves the centre of a 2027 software brief from screens to the integration layer: matching Peppol invoices to orders and goods receipts, routing exceptions to a person, and keeping Odoo, Teamleader and Exact Online in step without double entry.

Why is Crux Digits our pick for 2027?

Crux Digits is our pick because it is the only firm on this list whose own site publishes a fixed price per step, and it hands over all source code at the end.

Disclosure: Crux Digits publishes this list and is listed first. We say why, and who the others are better for.

• Three fixed steps: an AI audit at €2,500, a Production-ready MVP at €20,000 and production from €50,000, all excl. VAT. For Belgian businesses the VAT is normally reverse-charged.
• What we build is the software a package leaves out: integrations between Odoo, Teamleader, Exact Online, WinBooks or Octopus, Peppol invoices matched to orders and receipts with only the exceptions routed for approval, customer portals with roles and an audit trail, and AI where it saves measurable time.
• Ownership: at handover you receive the source code, documentation and access, with no licence fee to us for continued use. Another supplier can take over the code.
• We work alongside your ICT partner. Crux Digits is an AI partner, not an ICT partner: we do not run infrastructure, a service desk, systems management or a Peppol access point. Your ICT partner or internal team keeps the estate, and we build inside its standards.
• Delivery from the Utrecht region, in English and Dutch, with discovery and go-live on site in Flanders and the build done remotely.

Who we are not for: a French-language project in Wallonia or Brussels, since we work in English and Dutch; a multi-year programme with dozens of developers; an organisation that wants software and its day-to-day running from one supplier; or an Odoo rollout as such. Each of those has a better answer in the list below.

Which other software companies in Flanders and Belgium should you consider?

Eight Belgian firms met our criteria. They are listed alphabetically, each with the buyer it suits better than Crux Digits.

• AE, Leuven. A digital and AI consultancy of more than 450 people whose offerings include software engineering, legacy modernisation, data modernisation and hyperautomation, from strategy through to production. Best for: an organisation that wants strategy, data and software delivered by one Belgian firm at programme scale.
• Cegeka, Hasselt. A family-owned IT company headquartered in Hasselt with more than 9,000 employees, offering application services alongside outsourcing and managed services. Best for: an organisation that wants the software and the running of it under one contract, which we deliberately do not offer.
• Craftzing, offices in Antwerp, Ghent, Brussels and Leuven. It grew to 300 people in 2026 by acquiring innovation studio Made and partnering with enterprise architecture specialist INNOCOM, and its work spans strategy, enterprise architecture, service design and development. Best for: a transformation where architecture and service design must be settled before anything is built.
• Dynapps, Geel, with offices in Antwerp, Ghent and Namur. An Odoo Gold Partner with 280+ Odoo specialists across five European countries and ISO 27001 certification, which implements Odoo, recovers troubled Odoo environments, builds custom modules and offers hosting. Best for: an organisation whose core system is Odoo, or is moving to it, and wants implementation, modules and hosting from one specialist.
• In The Pocket, Ghent and Amsterdam. A digital studio of 200+ people for product and platform development, AI strategy and team enablement; its published cases include Daikin Europe and Tomorrowland. Best for: a customer-facing app or digital product where design and adoption matter as much as the integration.
• Kunlabora, Leuven. Builds custom software either as a project or as a team working inside the client's organisation, runs discover-and-design workshops, modernises legacy software and is ISO 27001 certified. Best for: an organisation that wants a dedicated team embedded on site for a long run.
• madewithlove, Leuven and Ghent. Staff engineers and fractional CTOs for software companies, offering software engineering, AI engineering, CTO as a service and technical due diligence, with 190+ SaaS audits behind it. Best for: a software company or SaaS scale-up that needs senior engineering leadership or an independent audit of its own codebase.
• Qframe, Kontich, part of Cronos Groep. Builds maatwerk software with teams composed per client, on .NET in the back end and JavaScript frameworks in the front end, in the cloud or on-premise; its published projects include UZA and Stad Brugge. Best for: an organisation standardised on Microsoft .NET that wants a long-running custom team.

None of these is a poor choice. Each is built for a size and shape of project, and the costly mistake is taking a six-week integration to a firm built for six-year programmes, or the reverse.

Which kind of firm fits which software project?

Match the supplier to three things: the size of team the work needs, how long it runs, and who runs it after go-live.

If the work is one bounded system that connects packages you already run, and your ICT partner will host and support it, a fixed-price build with code handover fits, which is our segment. If Odoo is your system of record and the gap sits inside Odoo, an Odoo partner such as Dynapps is the better route; custom code outside Odoo earns its place only when the process spans several systems. If you need several developers for years, look at Kunlabora, Qframe or AE. If you want build and run in one contract, Cegeka. If the product faces consumers, In The Pocket. If the architecture question comes before the build question, Craftzing. If you are a software company yourself, madewithlove.

One rule we apply before any of these choices: if nobody in your organisation can be named as the owner of the system after go-live, you are not ready to buy from any of them. The owner decides on change requests, signs off releases and answers the auditor's questions. Without that person, every supplier on this page will deliver software that drifts.

What should you ask a supplier about Odoo, Teamleader, Exact Online and Peppol?

Ask five integration questions before you compare prices, because each answer changes the scope.

1. Which Odoo API will you use? For Odoo 19 and later the answer should be the JSON-2 API, with a dedicated API key per integration and a stated key lifetime. Each JSON-2 call runs in its own database transaction and calls cannot be chained into one, so ask how a multi-step update recovers when step three fails.
2. How many Exact Online divisions are in scope? Almost all Exact Online REST API resource URIs require a Division parameter. A group with several legal entities in Exact means several divisions to configure, test and monitor.
3. Which Teamleader Focus objects are read and which are written? Teamleader publishes its API on its developer portal. Ask for the objects and actions to be listed in the scope, so that a change in the CRM does not become an unpriced change request.
4. Who provides the Peppol access point? Software connects to Peppol through a certified service provider, as the FPS Finance guidance explains. Your builder connects to that provider; it should not try to become one.
5. Where do exceptions land? Structured invoices remove retyping, not matching. A price difference, a missing goods receipt or an unknown supplier still needs a person. Agree who sees it, in which system, and what audit trail the decision leaves.

A supplier that answers all five in writing before quoting has already done part of the work. One that answers none is pricing a guess.

What does custom software cost in Belgium, and who publishes prices?

Of the nine firms on this list, only Crux Digits publishes a price on the pages we checked; the other eight quote per project.

That is not a criticism. Programme-scale firms price per engagement because their engagements differ, and a published price would mislead more buyers than it would help. It does mean that, for most of this list, you compare offers only after a sales process. To make those offers comparable, ask every supplier for the same four things: the price of the first bounded step in writing, how change requests are priced, whether any licence fee applies after handover, and what an exit looks like if you change supplier in year two.

A supplier unwilling to price a scoped audit or a first version is telling you the risk of overrun sits with you. A supplier that prices it is telling you it has done this before.

Where does Crux Digits fit next to your ICT partner?

Crux Digits builds the software and AI layer between your existing systems; your ICT partner keeps the infrastructure, the workplace and the helpdesk.

In practice that means we arrive with a scope your ICT partner can read: which systems we touch, which accounts and API keys we need, where the code will live and how it is deployed inside their standards. When the work is done, the code, documentation and deployment scripts sit in your repository, and your ICT partner or internal team can run it without us. If you want us to keep improving it, that is a separate, optional arrangement, never a condition of the build. Where AI is part of the system, our AI consultancy in Flanders covers the governance side.

For scope, process and the three fixed steps in Flanders, see custom software development in Belgium.

Last updated: 29 October 2026.

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