The verdict in three sentences
For an accounting practice of 20 to 50 staff, replacing your production software makes no sense: the expensive part is the management layer around it, engagement letters, time, billing and client portal. A custom extension at €30,000 to €80,000 connected to your existing tools pays back in 18 to 30 months against a suite at €40 to €90 per user per month. The decisive lever is time billing (+8% on average) and automated chasing, not technology.
Where the practice actually loses money
In most practices we audit, the client file lives in four places: production in the accounting software, documents in a DMS, time in a spreadsheet and engagement letters in Word files. Every handover creates a loss: unrecorded time, one-off assignments never billed, document chasing done by hand by assistants.
| Loss area | Typical situation (30-person practice) | 2026 order of magnitude |
|---|---|---|
| Time not recorded or logged at month end | 6 to 10% of real hours | €45,000 to €75,000 revenue per year |
| One-off assignments not billed | 15 to 25 jobs per year | €12,000 to €20,000 per year |
| Manual document chasing | 3 to 5 h per staff member per month | 1,000 to 1,500 h per year |
| Engagement letters out of date | 20 to 35% of the portfolio | Liability risk and frozen fees |
| Invoice issue delay | 25 to 40 days after period close | Working capital hit of €30,000 to €60,000 |
| Re-keying between tools | 2 to 4 h per week for admin | €5,000 to €9,000 per year |
These are estimates from comparable practices, but they show the scale: lost revenue often exceeds €100,000 per year for a 30-person firm.
Custom or market suite: the 2026 comparison
Integrated suites (practice management, engagement letter modules, client portals) cover standard needs well. Custom makes sense when your processes are specific: fixed-fee pricing by file type, outsourced payroll, a legal team, several offices across the region.
| Criterion | Market suite | Custom extension |
|---|---|---|
| Initial cost | €2,000 to €8,000 setup | €30,000 to €80,000 |
| Recurring cost (30 users) | €14,400 to €32,400 per year | €4,000 to €9,000 per year (hosting, maintenance) |
| Integration with production and DMS | Standard connectors, sometimes partial | APIs and sync on your real flows |
| Engagement letters | Generic templates | Generated from client type, e-signature |
| Client portal | Included, vendor branding | Your branding, document upload, deadline tracking |
| Go-live time | 1 to 3 months | 4 to 6 months in two phases |
| Code ownership | No | Yes, full reversibility |
Over five years, a suite costs €75,000 to €170,000 for 30 users, versus €50,000 to €125,000 for custom including maintenance. The gap widens as headcount grows.
The scope that pays most
We recommend delivering in two phases. Phase one (8 to 10 weeks) covers time entry on mobile and desktop, time versus budget per job, and automatic billing of overruns. Phase two adds the client portal with scheduled document reminders (D-15, D-7, D-2 before VAT or year-end deadlines), and engagement letter generation with renewal tracking.
| Module | Indicative budget | Measurable gain |
|---|---|---|
| Time and job budgets | €12,000 to €25,000 | +6 to 10% billed hours |
| Billing and reminders | €8,000 to €18,000 | Billing delay halved |
| Client portal and document upload | €10,000 to €25,000 | -60% manual chasing |
| Dynamic engagement letters | €5,000 to €12,000 | 100% of portfolio updated within 12 months |
| Partner dashboards | €4,000 to €10,000 | Profitability per client and per staff member |
Mini case study
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Sarah, managing partner of a 32-person practice in Leeds, bills €3.2 million a year. She invests €58,000 in a custom extension (time, billing, portal). First-year result: +8% on time-based fees, which make up 40% of revenue, i.e. €102,400 extra, plus 1,100 hours of chasing saved. With €6,500 of annual maintenance, payback comes in under 8 months.
FAQ
Do we need to leave our accounting production software?
No. The extension connects to your production tool via API or scheduled export. You keep your core tools and only add the management layer, which keeps the project at €30,000 to €80,000.
How long does the project take?
Allow 4 to 6 months in two phases, including 8 to 10 weeks for phase one (time and billing). We avoid year-end peaks: a May or September start is ideal.
Is client data GDPR compliant?
Yes, with UK or EU hosting, document encryption and access logs. Security accounts for 8 to 12% of the budget and includes a penetration test.
Does the client portal replace email exchanges?
In practice, 60 to 75% of documents go through the portal after 6 months. Automatic reminders at D-15 and D-7 are enough to switch most small business clients.
Can the project be financed?
Payment in three or four milestones is standard. Part of the spend can be depreciated over 3 years, smoothing the impact to about €20,000 per year for a €60,000 project.
Let's scope your project. Send us your current setup (tools, headcount, number of client files) and we will price a two-phase scope with indicative budget and timeline. 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.
