The verdict in three sentences
A partner extranet for a consulting firm in London is budgeted between 30,000 and 65,000 EUR, with partitioned project spaces and document versioning at its core. It cuts email back-and-forth by 40 % and secures client confidentiality, a critical issue in consulting. Plan for 3 to 5 months of development depending on the signature and reporting modules.
Module-by-module breakdown
A consulting firm has specific needs: strict partitioning, traceability and a premium image. Here are the 2026 ranges in EUR.
| Module | Indicative cost (EUR) | Lead time |
|---|---|---|
| Core (auth, roles, partitioned spaces) | 12,000 - 18,000 | 4-5 wks |
| Document management + versioning | 7,000 - 12,000 | 2-3 wks |
| Engagement & milestone tracking | 6,000 - 11,000 | 2-3 wks |
| E-signature (eIDAS) | 5,000 - 9,000 | 1-2 wks |
| Client dashboards & reporting | 5,000 - 9,000 | 2-3 wks |
| Messaging & project notifications | 3,000 - 6,000 | 1-2 wks |
A focused extranet (core + DMS + tracking + signature) sits around 34,000 to 48,000 EUR. eIDAS e-signature is often the differentiator that speeds up contracting.
Dedicated extranet vs generic tools (Drive, Slack, Notion)
Many firms cobble things together with consumer tools. 2026 comparison.
| Criterion | Dedicated extranet | Drive + Slack + Notion |
|---|---|---|
| Year 1 cost | 34,000 - 48,000 EUR | 3,000 - 8,000 EUR |
| Per-client partitioning | Strict, native | Fragile, manual |
| Confidentiality / compliance | High (logs, RBAC) | Medium |
| Brand image | Custom | Generic |
| Built-in signature | Yes | Separate third-party tool |
| Document-leak risk | Low | High (open shares) |
Generic tools are fine below 10-15 clients. Beyond that, confidentiality risk and wasted time justify a dedicated extranet.
Mini case study
Sophie, partner at a 22-consultant firm in London, ran 35 concurrent engagements through Drive and email, with a real risk of sharing the wrong document with the wrong client. After a 44,000 EUR extranet (core + DMS + tracking + eIDAS signature), email back-and-forth fell 40 % and contracting dropped from 8 days to 2 thanks to built-in signature. The admin time saved is about 0.4 FTE, i.e. ~24,000 EUR/year. ROI reached in 20 months, with sharply reduced confidentiality risk.
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FAQ
Why is an extranet safer than a shared Drive?
It enforces native per-client partitioning, granular roles (RBAC) and full access logging. A Drive relies on manual shares, where one mistake exposes a confidential deliverable.
Is e-signature really useful?
Yes: it cuts contracting by several days and provides legal probative value (eIDAS). For 5,000 to 9,000 EUR it speeds up engagement kickoff and payment.
Can the extranet be branded to the firm?
Yes, and it is a commercial asset: a client space in your brand reinforces premium positioning and reassures large accounts.
How long for deployment?
Expect 3 to 5 months. A first version (spaces + documents) can ship in 8-10 weeks to equip ongoing engagements.
What annual maintenance budget?
Between 10 and 15 % of the initial cost, i.e. 4,000 to 7,000 EUR/year, covering security, eIDAS updates and small enhancements.
Let's scope your project. Tell us your number of concurrent engagements, your signature and reporting needs, and we will frame the scope. 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.
