The verdict in three sentences
A custom case management platform for a law firm in London costs between 45,000 and 100,000 EUR, depending on the depth of time tracking, billing and document vault. Market solutions (Clio, LEAP, Actionstep) charge 50 to 120 EUR per user per month. Custom is justified once billing is complex (fixed fee, hourly, success fee) or the firm wants full control over confidentiality and data hosting.
The building blocks of a commercial firm
A firm doesn't sell documents, it sells qualified time. The tool must capture that time with no friction, tie it to a matter and turn it into a defensible invoice. Around it sit conflict-of-interest checks, a confidential document store and procedural deadline tracking.
| Module | Custom (EUR) | Lead time | Priority |
|---|---|---|---|
| Matter management | 11,000 - 20,000 | 5-7 wks | High |
| Time tracking + mobile entry | 9,000 - 17,000 | 4-6 wks | High |
| Fixed/hourly/success billing | 10,000 - 19,000 | 5-7 wks | High |
| Encrypted document vault | 8,000 - 15,000 | 4-6 wks | High |
| Conflict-of-interest checks | 5,000 - 10,000 | 3-4 wks | Medium |
| Secure client portal | 7,000 - 14,000 | 4-6 wks | Medium |
A full project takes 5 to 7 months, with migrating live matters being the most delicate point of the plan.
TCO and migration: the 5-year math
For a 15-lawyer firm, here is a 2026 order of magnitude comparing a vertical solution and custom development, migration included.
| Item | Market solution (15 users) | Custom |
|---|---|---|
| Upfront investment | 0 EUR | 72,000 EUR |
| Annual subscription | 16,200 EUR (90 EUR/user/mo) | 0 EUR |
| Matter migration | 6,000 EUR | 9,000 EUR (included) |
| Maintenance/evolutions/yr | partly included | 10,000 EUR |
| Sovereign hosting + backups | 2,400 EUR/yr | 4,200 EUR/yr |
| 5-year TCO | ~99,000 EUR | ~143,000 EUR |
The vertical solution stays cheaper short term. Custom pulls ahead as the firm grows, when billing breaks standard patterns, or when control over data hosting (professional privilege) becomes a selling point to large corporate clients.
Mini case study
Mr. Lefevre, partner at a 15-lawyer firm in the City, finds that 12% of billable time is lost for lack of real-time entry. On hourly revenue of 2.4 M EUR, that's about 288,000 EUR of unbilled time. He invests 72,000 EUR in a custom tool with mobile time entry and automatic reminders. By cutting the 12% loss to 5%, he recovers 7 points, or 168,000 EUR of extra billing in the first year. The tool pays back in five months, before any admin comfort gains.
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FAQ
Does GDPR require a specific hosting for a firm?
GDPR doesn't mandate location, but privilege and large clients often demand EU hosting, encrypted at rest. Budget 2,400 to 4,200 EUR per year for sovereign hosting with backups.
Can we migrate live matters without interruption?
Yes, via a progressive switch: new matters on the new tool, old ones migrated in batches. Migration runs 6,000 to 9,000 EUR and 3-5 weeks depending on volume.
Does mobile time tracking really change revenue?
Yes. Real-time entry cuts lost billable time by 40-60%. On a firm with 2 M EUR hourly revenue, each recovered point is worth 20,000 EUR.
What's the annual maintenance budget?
Between 12 and 18% of the investment, roughly 9,000 to 13,000 EUR for a 72,000 EUR project, security updates included.
Do we need a conflict-of-interest module?
For a commercial firm, yes: a systematic check when opening a matter avoids costly ethical risk. The module runs 5,000 to 10,000 EUR.
Let's scope your project. Tell us your lawyer headcount, your billing model and your hosting requirements, and we'll price the tightest possible 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.