The verdict in three sentences
For a practice with 35 staff and 1,400 client files, a custom workflow layer at EUR 30,000 to 70,000 connected to your existing production software costs less over 5 years than an all-in-one suite billed EUR 60 to 120 per user per month, and it avoids a risky migration. The realistic gain is 4 hours per week per staff member and +8% more billable time actually invoiced. Break-even usually lands between 8 and 16 months depending on scope.
Six tools for one practice: where the time goes
In most practices of this size, whether in London or Lyon, the core accounting production works fine. The problem is everything around it: time entries in a spreadsheet, engagement letters in Word, a separate document management system, missing-document chasers by email, tax deadlines in a shared file. Each switch between tools costs a few minutes, multiplied by 35 people and 45 working weeks.
| Task | Current tool | Time lost per staff member per week | What the custom layer does |
|---|---|---|---|
| Time entry | Spreadsheet + production software | 1 h 15 | One-click entry from the client file, Friday reminders |
| Engagement letters | Word + separate e-signature tool | 0 h 40 | Generated from templates, built-in e-signature |
| Finding documents | Separate DMS | 0 h 50 | Documents attached automatically to the client file |
| Chasing missing documents | Manual emails | 0 h 45 | Automatic reminders through a client portal |
| Tracking tax and payroll deadlines | Shared spreadsheet | 0 h 30 | Dashboard per client and per staff member |
| Total | 6 tools | about 4 h | 1 single interface |
Across 35 staff, those 4 hours add up to roughly 6,300 hours a year, close to 4 full-time equivalents absorbed by software friction.
Custom layer or all-in-one suite: the 2026 numbers
The all-in-one suite replaces everything, including production. The custom layer keeps your production software and plugs into it through an API or scheduled exports. Here is the comparison for a 35-person practice (2026 order of magnitude).
| Criterion | Off-the-shelf suite | Custom layer |
|---|---|---|
| Upfront cost | EUR 5,000 to 15,000 (migration, setup, training) | EUR 30,000 to 70,000 |
| Recurring cost | EUR 60 to 120 per user per month, i.e. EUR 25,200 to 50,400 a year | Maintenance at 12 to 15% of the build, i.e. EUR 3,600 to 10,500 a year |
| 5-year total cost | EUR 131,000 to 267,000 | EUR 44,400 to 112,000 |
| Production software migration | Mandatory, 3 to 6 months | None, connects to the existing tool |
| Fit with your processes | Limited to configuration | Complete |
| Code ownership | Revocable licence | Owned by the practice |
| Go-live time | 4 to 8 months | 3 to 5 months, delivered in phases |
The suite still makes sense for a practice that is changing production software anyway or has fewer than 10 staff. Above 25 people, the recurring bill outweighs the initial build.
Scope and budget by phase
Splitting the project into phases lets you fund it progressively and measure gains from the first month.
| Phase | Content | Budget | Timeline |
|---|---|---|---|
| 1. Time tracking and pre-billing | Production connector, mobile entry, monthly pre-billing | EUR 9,000 to 18,000 | 5 weeks |
| 2. Engagement letters | Templates aligned with professional standards, e-signature, annual renewal | EUR 6,000 to 12,000 | 3 weeks |
| 3. Client portal and document collection | Secure upload, automatic reminders, document status | EUR 8,000 to 20,000 | 5 weeks |
| 4. Partner dashboard | Profitability per client, workload per staff member, deadlines | EUR 5,000 to 12,000 | 3 weeks |
| 5. Security and hosting | Local hosting, single sign-on, audit logs, GDPR compliance | EUR 2,000 to 8,000 | 2 weeks |
| Total | 5 phases | EUR 30,000 to 70,000 | 3 to 5 months |
Mini case study
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James, managing partner of a 35-person practice in London, bills EUR 3 million in fees, 40% of it on time spent, i.e. EUR 1.2 million. He launches phases 1, 3 and 4 for EUR 55,000, plus EUR 7,000 of annual maintenance.
- Better time capture: +8% on EUR 1.2 million, i.e. EUR 96,000 of extra billing per year.
- Time freed: 6,300 hours a year. If only 20% is redeployed to billable work at EUR 70 per hour, that is 1,260 hours, or EUR 88,200.
- First-year cost: EUR 62,000. On the billing gain alone (EUR 8,000 per month), break-even comes in under 8 months.
FAQ
Do we have to replace our accounting production software?
No. The main production tools on the market offer an API or scheduled exports. The connector usually accounts for EUR 3,000 to 8,000 of the total budget.
How long before we see the first gains?
Phase 1 (time tracking) ships in about 5 weeks. Practices often see time-entry completion rise from 70% to over 90% by the second month.
How is client data protected?
Hosting is local with encryption, daily backups and access logs, for EUR 150 to 400 per month. The processing is documented in your GDPR record of processing activities.
Will staff actually use it?
The tool mirrors your own processes, which limits resistance. Two half-day training sessions are usually enough, and mobile time entry takes under 30 seconds per entry.
How do we depreciate the investment?
The build can usually be capitalised as an intangible asset and amortised over 3 to 5 years, i.e. EUR 11,000 to 23,000 a year for a EUR 55,000 to 70,000 budget. Your own accountant will confirm the treatment.
Let's scope your project. Tell us your current tools and priorities and we will price a phased custom layer between EUR 30,000 and 70,000, delivered in 3 to 5 months. 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.
