The verdict in three sentences
Start with the most painful area: matter management and e-signature, before the client portal. A vertical SaaS is enough to bootstrap; a custom build (EUR 30,000-75,000) becomes necessary as soon as you want compliant signature, a secure portal and proprietary automations. Professional privilege and client data confidentiality must guide every technical choice.
Where to start: the recommended sequence
There is no need to digitise everything at once. Here is the costed priority order for a London firm. 2026 order-of-magnitude estimates.
| Step | What it solves | Indicative budget |
|---|---|---|
| 1. Centralised matter management | End of paper/email scatter | EUR 12,000-28,000 |
| 2. Compliant e-signature | Signing delays slashed | EUR 6,000-16,000 |
| 3. Billing and time tracking | Reliable fees | EUR 8,000-20,000 |
| 4. Secure client portal | Premium client relationship | EUR 12,000-30,000 |
| 5. Automations and reporting | Firm-level steering | EUR 8,000-20,000 |
This sequence delivers value from week 6, then lets you reinvest the gains into the next steps rather than funding everything upfront.
Vertical SaaS vs custom build
Depending on your size and ambitions, the balance shifts. 2026 order-of-magnitude estimates.
| Criterion | Vertical SaaS | Custom build |
|---|---|---|
| Entry cost | EUR 0-3,000 | EUR 30,000-75,000 |
| Recurring cost | EUR 40-100/user/month | Maintenance EUR 700-2,200/month |
| E-signature | Basic | Compliant and integrated |
| Secure client portal | Rare | Custom |
| Confidentiality / privilege | To verify | Wired in from design |
| Rollout | 2-4 weeks | 8-14 weeks |
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Mini case study
James, partner in a 6-lawyer firm in London. Each engagement signature takes on average 4 days (paper back-and-forth) and 2 h of admin per matter. Across 120 matters/year at EUR 45/h, that is 120 x 2 x EUR 45 = EUR 10,800/year of time, before counting the delays. An e-signature module at EUR 12,000 plus matter management at EUR 20,000 cuts the delay to under a day and frees 65 % of that time. Full payback in about 18-24 months, with an immediate gain in client satisfaction.
FAQ
Where should a London firm start with legal tech? With centralised matter management (EUR 12,000-28,000) and e-signature (EUR 6,000-16,000), the two biggest sources of lost time and delay.
How much does a full custom legal tech build cost? Between EUR 30,000 and 75,000 depending on scope, plus EUR 700-2,200/month maintenance. A phased approach spreads the spend.
Is e-signature legally valid? Yes, provided you use a compliant method (identity, integrity, timestamp). The module is EUR 6,000-16,000 and must guarantee the evidential value of documents.
How do we ensure confidentiality and privilege? Secure hosting, encryption, granular access control and logging. These must be in the spec and wired in from design, not bolted on afterwards.
Is a client portal worth the investment? Yes for a firm seeking differentiation: it secures exchanges, cuts chasing and justifies premium positioning. Budget EUR 12,000-30,000 for a robust portal.
Let's scope your project. Tell us your lawyer count, your two biggest irritants and your starting budget: we build a phased roadmap with ROI. 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.
