The question I hear most after “what does a website cost” is this one. Usually from someone who already pays for three separate tools, and still ends up in Excel.
Custom software is a web application, integration or automation built for your process. Not a template. Not another plugin. You own the source code.
Below are the guide prices I use for quotes in 2026, what pushes that price up or down, and when you are better off keeping an existing package.
The short price list
All amounts exclude VAT. You get a fixed price after intake, not open hourly billing.
| Type | What you get | Guide price | Timeline |
|---|---|---|---|
| Integration or automation | Two systems talking, an export or notification flow | from €2,000 | 2–4 weeks |
| Website with booking system | Calendar, confirmation, optional deposit | €2,500–€5,000 | 3–5 weeks |
| Internal tool / small portal | Login, roles, a few screens | from €5,000 | 6–12 weeks |
| Web application | Own screens, reports, integrations | from €5,000 | 6–12 weeks |
| Custom AI tool or chatbot | Widget or tool on your content / data | from €750 + €50/month; with integration from €2,000 | 2–6 weeks |
A full web application with several roles, a data migration and two or three integrations often lands above that floor. How much exactly depends on scope, not on a magic hourly rate.
National agencies regularly quote €8,000 to €30,000 for the same work. That is not a law. It is what I see in quotes clients forward to me. My floor is lower because you work with one developer, without an account-manager layer.
What is custom software, in plain language?
Three things I do build, and one thing it is not.
Yes: an order overview that matches how you sell timber, boats or projects. A booking flow that handles date, product and payment in one go. An integration that replaces an email or a CSV.
No: “just tweaking” Microsoft 365, or an Excel file I make prettier. If the process does not exist yet, software is too early. Process first, then the app.
If you search custom software SME, this is the test: if you can explain it in one sentence to a new hire, I can build it. If you need three pages of A4, we start with a workshop, not with code.
What drives the price
Number of screens and roles
One screen for the owner is different from five roles (front desk, technician, admin, customer, admin). Each role is extra validation, extra permissions, extra test days.
Integrations
iDEAL via Mollie is predictable. An old accounting package with a half-documented API is not. Budget extra time per serious integration. Two clean REST integrations stay in the range above. An on-premise system without an API pushes the project up, sometimes doubles it.
Data that already exists
Migrating hundreds of orders or bookings is not an “import button”. It is mapping, cleaning, and a weekend where we both look along. Without migration a first version goes live faster. With migration you avoid the team keeping two systems.
Who supplies the copy and the rules
You know the exceptions. “No morning slot on public holidays.” “Discount only for contractors.” If those rules keep changing during the build, the timeline moves. I say that upfront, not afterwards.
What it actually was: Nijenhuis Botenverhuur
Nijenhuis Botenverhuur is a family business in Wanneperveen, next to Giethoorn. The old site had grown organically. Bookings partly ran through loose emails. Visitors looked for boat type, price and availability, then called anyway.
What is live now on nijenhuis-botenverhuur.com: a homepage with a booking widget, boat categories with prices and availability, destination pages for Giethoorn, Belt-Schutsloot and Wanneperveen, plus a seasonal blog. Reservations go through date, boat type and a cart. No loose email as the first step.
That is a website with a booking system, not an internal ERP. In my price list it belongs in the €2,500–€5,000 band (3–5 weeks), plus the content and landing pages. I do not put the exact invoice for this project here; that is the client’s. The lesson is: the expensive mistake was not the build, it was years of manual back-and-forth.
Houthandel Jan Sok and WAL Beschoeiing sit on the other side: a custom webshop plus order management, because a WordPress builder and a Shopify template could not carry their real order process. That is web-application work, not swapping a theme. See Jan Sok and WAL Beschoeiing.
Custom versus SaaS: three years on
A subscription of €80 to €250 per month feels cheap. Add it up.
| SaaS (typical SME package) | Custom (one-off + hosting) | |
|---|---|---|
| Year 1 | €1,000–€3,000 subscription, plus setup | €2,000–€8,000 build, plus €10–€50/month hosting |
| Year 2–3 | Same subscription, features you do not use | Hosting and small changes |
| Data and lock-in | Export if the platform allows it | Source code is yours |
| Process does not fit | Workarounds or a second tool | You change the software |
After three years SaaS is often cheaper if the package covers 80% of the work. Custom wins if you already need two tools plus Excel, or if the customer sees the process (booking, quote, order status).
I say that out loud because I do not make money if you stay on Mollie plus a calendar app. Stay there if it works.
Hidden costs (and what is not)
Hosting. For this kind of app I budget €10–€50 per month, depending on backups, email and seasonal peaks. Cheap shared hosting is a bad idea when login and payments sit on it.
Maintenance. No plugin circus. Yes: dependency updates, an SSL certificate, and the occasional change to your rules. That can be a one-off. No mandatory expensive monthly package.
AI tokens. Only if a language model is involved. A chatbot on website content is €50 per month with me (hosting + AI use). If it becomes hundreds of conversations a day, that rises.
Third-party licences. Mollie, Stripe, a maps API: their fees, not mine. You hear those upfront.
What you do not have to pay: “a licence on my CMS”. The code is yours. Documentation ships with delivery.
What you get in week 1 to 6
No black box. For an integration or a small app, a project with me looks like this.
Week 1. One-hour intake. I write the scope on one A4: who logs in, which action is “done”, which systems talk to each other. You correct that A4. That is the quote.
Week 2. First working screen or first test data through the integration. No six-week mockup round. You click in a staging environment.
Week 3–4. Finish the integration or booking flow, put exceptions in (holidays, discount, waitlist), you test with real examples. Bugs we find together go in the same sprint.
Week 5–6. Only for a web application: a second role, a report or a migration. Go-live with backups and a short manual. Then two weeks of aftercare for things that only show up in production.
More expensive than a SaaS trial. Cheaper than an agency that bills six weeks of “discovery” before you can click anything.
When custom is the wrong choice
- You do not have a fixed process yet. Write it down first, then build.
- One off-the-shelf package covers it, and your team will use it.
- The budget is under €2,000 and you expect a full portal. That will not happen. Start with one integration or one screen.
- You want “something with AI” without a source of truth (price list, FAQ, stock). Then the bot hallucinates, and you get the complaints.
Frequently asked questions
What does it cost to have a web application built? From €5,000 with me for an application with login, roles and own screens. Timeline 6–12 weeks. A simple integration starts at €2,000.
What does custom software cost? Same range. “Custom software” is the search term; the quote states what we build (integration, portal, booking, AI tool). Always ask for a fixed price and a one-page scope.
What is the price of having custom software built? The floor is €2,000. A serious SME web application more often lands between €5,000 and €12,000. Above that you are on multiple integrations, migration, or a product you later want to resell.
What does a custom portal cost? A small customer or supplier portal (login, status, documents) starts in the web-application band, from €5,000. More roles or an accounting integration sit on top of that.
What is custom software? Software written for your process, of which you receive the source code. Not renting a platform. Not a WordPress plugin that “almost” does what you want.
How long does it take? Integration: 2–4 weeks. Web application: 6–12 weeks. Intake and waiting for your test data sit in that. If decisions sit for three weeks, go-live moves with them. That is not a penalty, it is physics.
Who owns the code? You do. Including documentation. No vendor lock on my stack.
Want a range for your situation, not a brochure? Book a call. I will also say so if an existing package is cheaper. More about the service itself is on custom software and AI.