Client Portal Development Cost in London in 2026

The verdict in three sentences

A custom client portal or extranet for a B2B services SME costs 25,000 to 80,000 GBP in London in 2026 and 15,000 to 45,000 EUR excl. VAT in Paris, for 8 to 16 weeks of development. The SaaS alternative runs at 15 to 50 EUR per user per month, unbeatable under 30 users but expensive and rigid beyond that, especially if your clients also need access. Custom makes sense when it saves the service team 4 to 10 hours a week and plugs into your existing tools (ERP, invoicing, ticketing).

Why services SMEs move to a portal

A maintenance company, a consultancy or an industrial subcontractor exchanges dozens of documents with clients every week: quotes, work orders, reports, invoices, incident tickets. As long as everything goes through email, the service team spends its time finding the right version, chasing a signature or answering "where is my request?". The portal centralizes these exchanges in a secure space where clients view, download, approve and open a ticket without calling.

A basic portal (accounts, documents, tickets) therefore starts around 15,000 EUR; a full extranet with payments and ERP integration reaches 40,000 to 45,000 EUR.

Custom or SaaS: the real comparison

SaaS client portal and helpdesk tools are excellent for getting started. The math changes when the number of accounts grows, when the client journey is specific or when deep integrations are required.

The tipping point is usually between 30 and 50 users, or as soon as the SaaS charges every client contact as a paying seat.

The specification that prevents overruns

Budget overruns on a portal almost always come from three grey areas: access rights (who sees what at the client), migration of existing data and integrations. A 2 to 3 day scoping workshop, billed 2,000 to 4,000 EUR, settles these points, produces clickable mockups and allows a fixed-price quote. Also plan for hosting in the UK or EU, GDPR compliance (access logs, retention periods) and annual maintenance at 10 to 15% of the initial cost.

Mini case study

Claire runs a 45-person maintenance SME in Paris serving 120 B2B clients. Her 3-person service team spends about 8 hours a week finding reports, resending invoices and answering status requests.

She invests 28,000 EUR in a portal (documents, tickets, invoices, ERP connector) plus 350 EUR a month for maintenance and hosting. Gain: 7 hours a week at 38 EUR loaded hourly cost, about 12,200 EUR a year, plus invoices paid 2 days faster when viewed online. Over three years, the portal costs 40,600 EUR and saves more than 36,000 EUR in time alone; the SaaS equivalent for 120 clients and 3 agents would have exceeded 50,000 EUR. A London firm with the same scope would have budgeted 25,000 to 80,000 GBP.

FAQ

How much does a custom client portal cost in London in 2026?

Roughly 25,000 to 80,000 GBP depending on modules. In Paris the range is 15,000 to 45,000 EUR excl. VAT, and a nearshore team in Dakar can deliver the same scope 30 to 45% cheaper.

How long does development take?

From 8 to 16 weeks including scoping. A useful first version can ship in 8 weeks, then grow through 2 to 4 week iterations.

When should I choose SaaS instead?

Under 30 users, with a standard need and no ERP integration, a SaaS at 15 to 50 EUR per user per month remains the cheapest option. Custom takes the lead beyond 30 to 50 accounts.

Is the portal GDPR compliant?

Yes if hosting is in the UK or EU, access is logged and retention periods are defined. These items usually add 1,000 to 3,000 EUR to the project.

Can the portal be built in Senegal to cut costs?

Yes, a nearshore team in Dakar bills 250 to 400 EUR a day versus 600 to 900 EUR in Paris, a 30 to 45% saving for the same scope, on GMT, the same time zone as London in winter.

Let's scope your project. Describe your current client exchanges, number of accounts and tools: we price a portal between 15,000 and 45,000 EUR, delivered in 8 to 16 weeks. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.