Your clients, suppliers or own team email and call about the same things: a status, a document, an invoice. Someone looks it up, replies, and does it again tomorrow. A portal fixes that by giving that group direct access behind their own login. But which portal do you need, what does it cost, and how do you approach a project like this? This guide answers those questions step by step, without the sales pitch.
What exactly is a portal?
A portal is a secured online environment where a fixed group of users log in to view their own data, share documents and handle tasks themselves. The difference from a regular website is the login and processing layer: a website informs everyone the same way, a portal shows each user exactly their own data and lets them actually work with it.
Technically, a portal is a web application: software that runs in the browser, without installation, with roles, permissions and a database underneath. That makes it a different project from having a site built. You are not creating pages to read, but screens to work in, with logic that checks whether what someone is doing is actually allowed.
What types of portals are there?
Most SME questions fall into five types. They share the same building blocks (login, roles, dashboards, notifications), but differ in who logs in and what that person may see and do. Choose based on whom you want to relieve, not on what sounds modern.
| Portal type | For whom | What it solves |
|---|---|---|
| Customer portal | Your clients | Viewing and handling status, documents, invoices and requests themselves |
| Employee portal (intranet) | Your own team | Leave, expenses, internal requests, knowledge base and documents |
| Supplier portal | Your suppliers | Orders, purchase prices, delivery status and invoices in one place |
| Partner or dealer portal | Resellers and partners | Orders, marketing material, commissions and price agreements |
| Member portal | Members of an association or union | Dues, events, member information and communication |
The customer portal is by far the most requested. Want to go deep on that one, with five concrete examples from accountancy, real estate and law, plus cost per module? Read our separate guide on building a customer portal with examples. This page stays broader: which portal fits your situation, and what is involved in general.
When does a portal pay off?
A portal pays off once the same questions or actions keep repeating and you can hand them over to the user. The business case rarely sits in extra revenue, but in hours your team no longer spends on repetitive work. If you recognise one of these five signals, a portal is worth considering.
- Recurring status questions. Clients or suppliers keep calling for the same update. A dashboard with live status removes those calls.
- Documents back and forth. Receipts, contracts, requests: when that runs through email, something gets lost and it lacks an audit trail.
- Self-service, 24/7. People want to view or request something outside office hours without bothering anyone. According to an analysis in Harvard Business Review, 81 percent of customers try to solve a problem themselves before reaching out (Harvard Business Review).
- Personalised data per user. Every client, employee or supplier sees only their own data, permissions and history.
- Systems that do not talk to each other. Data you retype daily between two packages is a sign that a portal with integrations will pay for itself.
Custom or an off-the-shelf package?
Choose custom only when an existing package or no-code tool does not cover your process. Many accounting, CRM and HR systems already have a built-in portal module; it is cheap and quick to go live, but does not bend to a way of working of your own. Custom pays off the moment you hit a real limit, not before.
Work through this order. Does your current software already have a portal function that suffices? Use it. Can a no-code solution like Airtable or Notion carry a first version? Test it there cheaply. Only once usage is proven and the standard options pinch (your own role structure, specific integrations, your brand, your logic) does custom start to pay off. Torn between a web app, a SaaS product and a real platform? Read the comparison of web app vs SaaS vs custom platform.
What does it cost to have a portal built?
Having a portal built costs roughly €8,000 to €18,000 for a basic version, €20,000 to €50,000 for a full portal, and €50,000 or more for a large portal with multiple roles, integrations and AI features. The price is driven by the number of modules, roles and integrations, not by the hourly rate alone. On top of that, budget 10 to 20 percent of the build price per year for hosting and maintenance.
| Scope | What is included | One-off investment | Timeline | Per month |
|---|---|---|---|---|
| Basic | Login with MFA, dashboard, one module (documents or status) | €8,000 to €18,000 | 2 to 4 weeks | €150 to €400 |
| Standard | Several modules, notifications, one to two integrations | €20,000 to €50,000 | 6 to 10 weeks | €400 to €800 |
| Large | Multi-role, multi-tenant, audit logs, several integrations, AI | €50,000 and up | 3 to 5 months | €800 to €1,500 |
That is the short version. The full breakdown per component, with a worked example over several years, lives in our pricing guide on custom software costs. With every quote, watch what you are actually buying: a fixed price on a well-defined scope, or an hourly rate on a vague idea. The latter is a blank cheque.
How does the build process work?
Having a portal built runs in five phases: discovery, design, build, test and launch. The craft is not in the building itself, but in getting sharp on what you are building before a single line of code is written. According to research by McKinsey and Oxford, 45 percent of large IT projects run over budget (McKinsey), and the biggest lever against that is tight preparation.
- Discovery (1 to 2 weeks). Needs, processes, roles and data mapped out. Result: a scope document with screens, roles and integrations, plus a fixed price. This is a paid phase, not a free chat.
- Design (1 to 2 weeks). Wireframes and a clickable prototype. You click through the portal before anything is built, so wrong assumptions surface now.
- Build (2 to 12 weeks). The actual development in two-week sprints, with a demo at the end. Insist on seeing a working version every two weeks.
- Test (in parallel plus a final sprint). Automated tests, acceptance tests with real users and a security scan against the OWASP Top 10.
- Launch and onboarding. Go-live with monitoring, a handover document and a plan to actually get users onto the portal.
Want to validate quickly without building everything at once? Start with a minimal version. How to phase that is covered in building an MVP: approach and phases. A concrete example of a custom platform from first conversation to production is in the Mastone case study.
Integrations: a portal rarely stands alone
A portal only becomes valuable when it automatically exchanges data with your existing systems. Otherwise you still retype everything and double the work. Good integrations save your team hours per week; poor ones break with every update. Start with the two most important, and only add the rest after go-live.
- Accounting. Exact, AFAS, Moneybird or Twinfield for invoices, orders and customer data.
- CRM. HubSpot, Pipedrive or Salesforce, so the portal and sales share the same customer data.
- Payment providers. Mollie, Stripe or Adyen for payments and subscriptions in the portal.
- Email and notifications. Transactional mail via Postmark or Resend, plus in-app alerts.
Most business packages offer an API that allows this. How such an integration works technically and what it costs depends on the system and the direction of the data. A supplier portal that writes orders back to your ERP is more complex than a customer portal that only pulls invoices.
What security and GDPR requirements apply?
A portal processes personal data, so security is not an afterthought but a design choice from sprint one. The Dutch Data Protection Authority expects appropriate measures under Article 32 of the GDPR (Autoriteit Persoonsgegevens). For almost every portal, that means at least the following.
- Encryption in transit and at rest. TLS 1.2 or higher, no exceptions.
- MFA for every user. Two-step verification, not optional.
- Role-based access control. Each role sees only what it may, enforced at database level and not only in the frontend.
- Audit logs, at least 12 months. Who viewed or changed what, and when.
- EU hosting. At Hetzner Germany, AWS Frankfurt or a Dutch provider, with a data processing agreement per sub-processor.
What technology sits under a good portal?
The technology under a portal should be boring and mature, not exciting. A modern, widely used stack means you can easily find developers later who will take it over, and that you are not locked into a single supplier. According to the Stack Overflow Developer Survey 2025, PostgreSQL has been the most-used database for years, and React and TypeScript are among the most-used web technologies (Stack Overflow Developer Survey 2025). That is exactly why they are good default choices.
Two requirements weigh more than the exact names. The first is code ownership: all source code in a Git repository under your account, with deploy instructions another party can follow. Without that, you rent software instead of owning it. Read why that matters in code ownership and vendor lock-in. The second is speed: slow screens cost usage directly. The probability that someone bounces rises by 32 percent as a page goes from 1 to 3 seconds of load time, according to Think with Google (Think with Google). A modern stack meets that bar by default.
Where should you have a portal built?
You can have a portal built by a freelance developer, a small dev studio or a larger software house. For SMEs, a small studio with short lines is usually the best balance: you talk directly to the builders, the price is keener than at a big house, and continuity is greater than with a single freelancer who could fall ill. More important than the type is what you agree on.
Ask every party three things: do I get a fixed price for a clear scope, do I get the code in ownership, and what stack do you build on? A good partner answers those without dodging. More on that trade-off is in software studio vs freelance developer and in our complete guide to having custom software built.
How do you start, concretely?
Start small and sharp. Write down in thirty minutes which questions or actions repeat most now, and for whom. Then pick one audience to start with (customers, employees or suppliers) instead of wanting everything at once. Only then book a paid discovery instead of a free quote based on a hunch. A discovery of one to two weeks yields a scope document that lets you compare every quote on equal footing and makes most hidden extra work disappear.
Book a free intake call if you would like to look at it together. No sales pressure, just grounded advice on the route that fits your goal and budget.
TopDevs is a Dutch software agency that builds custom software, AI integrations and automations.
