What a Custom Client Portal Really Costs to Build (Berlin, 2026)

The verdict in three sentences

A custom client portal costs between 18,000 and 45,000 EUR to build in 2026, while an equivalent SaaS bills 8 to 25 EUR per user per month. The financial tipping point sits around 40 active users over 24 months, once you factor in maintenance (12-18 % of the build per year) and hosting. If your business has strong specifics (workflows, ERP integrations, billing), custom pays back fast; otherwise, SaaS remains unbeatable at launch.

What a custom portal really costs

The budget depends on functional scope: authentication, document area, billing, messaging, dashboard. Here are the 2026 orders of magnitude seen on the market.

On top of that come recurring costs, often underestimated in early quotes.

SaaS vs custom: the real 24-month math

To decide, project total cost of ownership. Take a Standard portal at 30,000 EUR versus a SaaS at 15 EUR/user/month.

Custom here includes the build (30,000 EUR) + maintenance 15 %/year (9,000 EUR over 2 years) + hosting. Above 100-150 users, or when SaaS does not cover your workflows, custom becomes clearly cheaper.

Mini case study

Clara, CFO of a mid-sized trading firm in Berlin (55 staff), managed her 90 reseller clients through emails and a shared spreadsheet. A support SaaS at 18 EUR/user/month for 12 agents cost her 5,184 EUR/year, with no built-in billing. She commissioned a Standard portal at 31,000 EUR (build) + 4,650 EUR annual maintenance. Gains: 6 hours/week saved on document tracking (about 14,000 EUR/year in value), and automatically reconciled billing. Estimated payback: 20 months, hosting included at 70 EUR/month.

FAQ

Is an MVP enough to start? Yes, in 70 % of cases. An MVP at 18,000-24,000 EUR covers authentication, documents and notifications, delivered in 6-9 weeks. You add billing or ERP in a second phase once usage is validated.

Is maintenance really mandatory? It is not legally mandatory, but a portal without maintenance becomes technical debt within 12-18 months. Budget 12-18 % of the build cost per year for fixes, security updates and small enhancements.

Can we migrate from SaaS to custom later? Yes, but plan a data migration budget of 3,000 to 8,000 EUR depending on volume and export ownership. Check from the outset that your SaaS allows full export (API or CSV).

Which hosting stays GDPR-compliant? A host with EU datacenters (Hetzner, OVH, Scaleway) at 40-120 EUR/month is enough for most portals. Data stays in the EU, which simplifies your processing register.

How long from quote to go-live? Count 6-9 weeks for an MVP and 12-18 weeks for an advanced portal, scoping included. The limiting factor is usually your teams' availability for testing and content delivery.

Let's scope your project. MVP portal from 18,000 EUR or an advanced solution with ERP integration: tell us user count, priority features and target date. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.