"What does a client portal cost?" is one of the most common questions development agencies get — and the answer is almost always "it depends". True, but useless when you need to budget. So here are concrete ranges for the three routes to a client portal in 2026, including the costs that only show up later.
The three routes and their price tags
1. Development agency: €15,000 – €40,000
A custom portal from an agency starts around €15,000 for a basic version (login, dashboard, documents) and heads towards €40,000 once integrations, workflows or full branding come in. At hourly rates of €80–€150, every change adds up.
What the quote doesn't mention: maintenance (often 15–20% of the build cost per year), change-order fees when requirements evolve, and the lead time — three to six months is normal.
2. Off-the-shelf SaaS: €5 – €25 per user per month
Ready-made portal software looks cheap, but charges per seat. With 200 clients in your portal you quickly reach €1,000+ per month — permanently. And your process has to adapt to the product, not the other way round.
What the price doesn't mention: the features you're missing, the hours lost to workarounds, and the exit costs if you ever want to leave (your data lives in their system).
3. AI-built custom software: from €99 per month
The newest route: an AI development team like Turtleship builds a custom portal within a subscription. You start from a ready-made client-portal building block (login, dashboard, documents, notifications) and extend it step by step — with an estimate before every step, so there are never surprises.
The honest part: a complex portal still costs more build steps (credits) than a simple one. The difference is predictability — you see the estimate before you approve — and the absence of hourly rates and per-seat pricing.
Side by side
| Agency | Off-the-shelf SaaS | AI-built custom | |
|---|---|---|---|
| Upfront | €15,000–€40,000 | €0 | €0 (free start) |
| Ongoing | 15–20% maintenance/yr | €5–25 per user/mo | from €99/mo |
| Lead time | 3–6 months | days | days (basis) – weeks |
| Fits your process | yes | partially | yes |
| Owns code & data | usually you | the vendor | you |
| Changes | change-order quote | wait for the roadmap | new request, estimate first |
Worked example: 200 clients in your portal
Abstract ranges only become concrete when you run the numbers. Say you're an accounting firm with 200 clients who submit documents, review reports and approve deliverables.
- Off-the-shelf SaaS: at an average €8 per user per month you pay €1,600 per month, or €19,200 per year. Structural, and the bill grows with every new client.
- Agency custom: a one-off €25,000 or so for a portal of this size, plus 15–20% maintenance per year (€4,000–€5,000). The number of users doesn't matter, but every change is a change-order quote.
- AI-built custom: from €99 per month (€1,188 per year), regardless of the number of users. Extensions go one build step at a time, with an estimate up front.
Over three years: SaaS lands around €57,600, the agency around €38,000 (build plus maintenance), and the AI route starts at roughly €3,600. In fairness: a portal with many integrations and exceptions costs extra build steps on the AI route, and so more than the entry rate. But even with a generous margin, the gap stays an order of magnitude.
What to check (whichever route you pick)
- Ask what change number five costs. The build price is one thing; what does it cost when you want something different after three months? That's where the routes really diverge.
- Check where your data lives. A client portal processes personal data; European hosting and a GDPR-compliant setup should be standard, not optional.
- Price the exit. Who owns the code? Can you take your data? A low entry price with lock-in is more expensive than it looks.
Conclusion
In 2026, a client portal no longer has to be a €30,000 project. The agency route still makes sense for deeply integrated, highly complex portals with a generous budget. For most SMBs and independents the maths has changed: an AI-built custom portal, from €99 per month, production-ready and yours. Set that against what having software built costs in general, and a portal subscription quickly comes out ahead.
A client portal isn't the only building block, by the way: in the same way you can set up a supplier portal or a custom employee portal. What those variants cost is covered in what a supplier portal costs and what an employee portal or intranet costs.
Curious how that works? See the client portal page or start free and get a working foundation within days.