Direct answer
There's no single number, but a real shape: a portal with one client role, document sharing and a status view sits at the cheapest end. Add a second role (team members reviewing client submissions), billing links, or a CRM sync, and cost moves up from there. A Product Scope conversation gives you a real range for your actual roles and integrations, not a category-label estimate.
Why "client portal" alone doesn't tell you the price
A single-role portal that only shows status and lets a client download a document is a fraction of the cost of a multi-role portal with approvals, messaging and a billing integration — both get called "client portal" in a sales conversation, but the scope behind that label can differ by several multiples.
What actually drives cost up
- Number of distinct roles (client, team member, admin) and what each is allowed to see
- Document handling — simple storage vs. a request/collection workflow chasing what's still outstanding (see [Client Document Collection Automation](/client-document-collection-automation/))
- Whether clients need to approve or sign off on deliverables in-portal (see [Client Approval Automation](/client-approval-automation/))
- Billing or payment links, if included
- Whether it connects to a CRM or project tool you already use, and how many of them
What to build first, to control cost early
Status visibility and document access are almost always the highest-value first features — see Client Portal Features: What Should You Build First? for the priority order we actually recommend, since building everything at once is the single biggest driver of an inflated first-version cost.
How to get a real number
Through a Product Scope conversation once your actual roles, documents and integrations are understood — not a generic "portal packages" page, since the honest range depends entirely on the factors above.
Questions
Is a client portal cheaper than a full web application?+
Often, if scope stays narrow (one client role, status and documents) — but a multi-role portal with billing and CRM sync can cost the same as a general web application, since it effectively is one. See Web Application Development Cost for the broader shape.
Does this include ongoing hosting and maintenance?+
Hosting and maintenance are typically scoped and priced separately, agreed upfront rather than assumed.
Can I start with a narrow scope and add features later?+
Yes — starting with status visibility and document access, then adding messaging or approvals later, is usually the more honest path than committing to full scope before you know clients will actually use it.