Practice management software for an accounting firm: custom build vs packaged

The verdict in three sentences

An accounting firm with 25 staff managing 900 client files across a production tool, a timesheet spreadsheet and a separate document management system pays twice: in licences and in lost hours. Keeping the packaged production software and building a custom module for engagements, engagement letters and time tracking (EUR 30,000 to 60,000 excl. VAT) makes profitability per client file visible every month. The realistic gain is 2 hours per employee per week, more than 2,000 billable hours recovered per year.

Where the firm loses time and margin

In Lyon as in most markets, the profession has stacked tools: bookkeeping production, review, tax returns, document management, e-signature, and an Excel file for time. Engagement letters are drafted in Word, signed and filed with no link to the hours budget. The result: the partner finds out at year end that a file billed at EUR 4,800 consumed 85 hours instead of 50.

These are 2026 orders of magnitude observed in firms of 20 to 40 people. The key point: the loss comes less from the production software than from the missing link between engagement letter, time spent and billing.

Packaged software or custom module: the 2026 comparison

The vendor suite fits if the firm accepts its processes. Custom becomes worthwhile when the firm runs atypical engagements (statutory audit, payroll advisory, furnished rental clients, company formations) or when the partner wants to manage margin per file without Excel rework. At 25 users, an extra EUR 35 per month represents EUR 10,500 per year: the custom module pays back in 3 to 5 years on that line alone, and much faster once recovered hours are counted.

What a well-designed engagement tracking module contains

Security and compliance: EU hosting, encryption, access logging, GDPR compliance and respect for professional secrecy. These requirements go into the specification from the scoping phase.

Mini case study

Claire, partner at a 25-person accounting firm in Lyon, manages 900 client files and EUR 2.4M in fees. She keeps her production software and orders a custom module at EUR 45,000, with EUR 650 per month for maintenance.

• Time recovered: 2 h per week × 25 staff × 44 weeks = 2,200 h. If only 40% is re-billed at EUR 75, that is EUR 66,000.
• One-off engagements better captured: +EUR 18,000 per year.
• First-year cost: 45,000 + 7,800 = EUR 52,800.

Net first-year gain: about EUR 31,000, payback in 7 to 8 months. In later years, only maintenance remains.

FAQ

Do we need to replace our accounting production software?

No. The custom module plugs into the existing tool through an API or scheduled import. The firm keeps its EUR 60 to 120 per user licences and only adds the management layer.

How long does the project take?

Allow 3 to 5 months: 3 weeks of scoping, 8 to 12 weeks of development, then 3 to 4 weeks of acceptance testing with two pilot managers. A rollout outside tax season (June to September) is recommended.

Do engagement letters stay compliant with professional standards?

Yes, the templates come from the firm and are reused as-is with dynamic fields. E-signature is time-stamped and an amendment is generated as soon as a 20% budget overrun is detected.

Will staff really log their time?

Adoption exceeds 90% when entry takes less than 2 minutes a day on mobile and replaces an existing tool. Weekly approval by the manager does the rest.

Who owns the code and the data?

The firm. Source code and data are delivered and hosted in the EU, with reversibility written into the contract.

Let's scope your project. Send us your headcount, current tools and your three priority reports: we will price a module between EUR 30,000 and 60,000 with a 3 to 5 month schedule. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.