The verdict in three sentences
A custom client portal for a B2B services firm is budgeted between 18,000 and 40,000 EUR (excl. VAT) in 2026 for a first working MVP (authentication, roles, project tracking, documents, invoices). Expect a 10-to-16-week timeline at a 450-700 EUR day rate, then annual maintenance of 8-15% of the build cost for upkeep and evolutions. The ROI comes mainly from a 20-40% reduction in support emails and reclaimed administrative time.
What a client portal covers and what it costs
A client portal is not a brochure site: it is an authenticated web app with data specific to each client. Cost depends mostly on the number of modules and the granularity of access rights.
| Module | 2026 scope | Range (EUR excl. VAT) |
|---|---|---|
| Auth + roles | Secure login, passwords, 2FA, admin/client roles | 3,000 - 6,000 |
| Project/ticket tracking | Statuses, milestones, history, comments | 4,000 - 9,000 |
| Document space | Upload, versions, secure sharing | 2,500 - 5,000 |
| Invoicing | View invoices, payment status, PDF export | 3,000 - 7,000 |
| Notifications | Email + in-app, automated reminders | 1,500 - 4,000 |
| Client dashboard | Summary view, custom indicators | 2,500 - 6,000 |
| Design + brand integration | Custom UI, responsive, accessibility | 3,000 - 6,000 |
A lean MVP (auth + projects + documents + invoices) fits the 18,000-28,000 EUR range. A full version with advanced dashboard and fine-grained notifications climbs toward 35,000-40,000 EUR.
Total cost of ownership: don't forget after launch
The build is only half the story. A portal lives, integrates and evolves. Here are the recurring lines to plan for from the quote stage.
| Line item | 2026 detail | Order-of-magnitude cost |
|---|---|---|
| Hosting (Scaleway/OVH) | Server + managed Postgres, backups | 40 - 150 EUR/month |
| Maintenance (TMA) | Fixes, version upgrades, small evolutions | 8 - 15% of build/year |
| Invoicing integration | Connector to Sage, Xero or accounting API | 3,000 - 8,000 EUR one-off |
| Support & SLA | Guaranteed response time, on-call | 150 - 600 EUR/month |
| Yearly evolutions | New modules, dashboards | 5,000 - 15,000 EUR/year |
For a 30,000 EUR build, plan for roughly 2,400 to 4,500 EUR of maintenance per year, plus hosting. That is the price of reliability: a portal your clients use daily cannot go down without a response.
Mini case study
Sarah runs a 22-person HR consulting firm in London. Her project managers spent about 6 hours a week re-sending deliverables, reports and invoices lost in client inboxes. At a 50 EUR loaded hourly cost, that is 300 EUR/week, roughly 14,000 EUR/year of admin time.
She invests 26,000 EUR in an MVP portal (auth, engagement tracking, documents, invoices) delivered in 12 weeks. By month 3, inbound support emails drop 35% and admin time falls to 3.5 hours/week. Estimated annual saving: around 6,000 EUR in time, plus a commercial effect (clients renew more easily thanks to transparency). Estimated payback: around 20 to 24 months, maintenance included.
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FAQ
What is a credible minimum budget for a client portal in 2026?
Expect 18,000 EUR for an honest MVP (auth, projects, documents, invoices). Below 12,000 EUR you get a generic client area with no business logic, rarely profitable over the medium term.
How long before it goes live?
An MVP portal ships in 10 to 16 weeks depending on the number of modules and integration complexity. Connecting your invoicing tool typically adds 2 to 3 weeks.
Should I prefer an off-the-shelf SaaS?
A client-portal SaaS costs 15 to 60 EUR/user/month but adapts poorly to your processes. Custom becomes profitable beyond 2 to 3 years if you have specific workflows or many users.
Can the portal connect to my invoicing?
Yes. A connector to Sage, Xero or an accounting API costs 3,000 to 8,000 EUR and eliminates double entry. It is often the highest-ROI module.
What annual maintenance cost should I plan?
Between 8 and 15% of the build cost per year, i.e. roughly 2,400 to 4,500 EUR for a 30,000 EUR portal, plus hosting (40-150 EUR/month).
Let's scope your project. Tell us your priority modules (tracking, documents, invoices), your number of active clients and an indicative budget, and we'll price the most profitable MVP. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
