The verdict in three sentences
An independent staffing agency placing 150 temps a week and still keying in paper timesheets loses about 15 hours of data entry every week and piles up costly payroll errors. A specialist vendor at 300 to 900 EUR excl. VAT a month covers payroll and the French DSN social declaration, but its timesheet module is often rigid for client companies. A custom timesheet module at 25,000 to 50,000 EUR excl. VAT, plugged into the vendor, digitises client approval, e-signature of assignment contracts and DSN export, in 3 months.
Specialist vendor or custom module: the 2026 comparison
| Criterion | Specialist staffing vendor | Custom module + payroll vendor |
|---|---|---|
| Subscription | 300 to 900 EUR excl. VAT per month | 300 to 900 EUR excl. VAT per month (payroll kept) |
| Initial development | 0 to 3,000 EUR of configuration | 25,000 to 50,000 EUR excl. VAT |
| Module maintenance | Included | 300 to 700 EUR excl. VAT per month |
| Mobile timesheet for the temp | Basic or missing | Clock-in, breaks, premiums |
| Approval by the client company | By email, as PDF | One-click client portal, automatic reminders |
| E-signed assignment contracts | Paid option per signature | Built in, 0.50 to 1.50 EUR per signature |
| Premium rules by agreement and client | Limited configuration | Custom rules engine |
| Go-live time | 1 to 2 months | 3 months |
Regulatory reminder: in France the assignment contract must be sent to the temp within 2 working days of starting the assignment. A time-stamped e-signature secures this deadline and avoids reclassification as a permanent contract, which easily costs more than 10,000 EUR per case at the labour court.
Functional scope and cost
| Block | Indicative cost excl. VAT | Expected gain (2026 order of magnitude) |
|---|---|---|
| Temp app: hours and breaks entry | 6,000 to 12,000 EUR | No more lost or illegible paper timesheets |
| Client portal: approval and disputes | 5,000 to 10,000 EUR | Timesheets approved in 24 h instead of 4 days |
| Premium engine (nights, Sundays, overtime) | 5,000 to 10,000 EUR | Payroll errors divided by 5 |
| Assignment contracts with e-signature | 3,000 to 7,000 EUR | 2-day legal deadline met 100% of the time |
| Export to payroll vendor and DSN | 4,000 to 8,000 EUR | Payroll variables imported with no re-keying |
| Automatic client invoicing | 2,000 to 5,000 EUR | Invoices issued on D+1 instead of D+7 |
DSN export does not mean the module redoes payroll. It prepares the variables (regular hours, premium hours, end-of-assignment allowances, paid leave) in the format the vendor expects, and the vendor produces payslips and the monthly DSN. This separation limits legal risk and maintenance cost.
A 3-month plan
| Phase | Duration | Deliverable |
|---|---|---|
| Audit of timesheets and client agreements | 2 weeks | Catalogue of premium rules |
| Temp and client mock-ups | 2 weeks | Journeys tested with 10 temps |
| Development and payroll connector | 6 weeks | Module in acceptance testing |
| Pilot with 3 client companies | 2 weeks | Adjustments |
| Rollout to all clients | 1 week | Paper eliminated |
Mini case study
Sophie, manager of an independent staffing agency in Lille, handles 150 temps a week in construction and logistics. Her payroll officer spends 6 minutes per paper timesheet, i.e. 15 hours a week, and about 3% of payslips need correcting.
She invests 38,000 EUR excl. VAT in a custom module. Data entry saved is 15 hours over 47 weeks, or 705 hours valued at 35 EUR: 24,675 EUR a year. Payroll errors fall from 3% to 0.5% on 7,800 payslips, i.e. 195 corrections avoided at 60 EUR each: 11,700 EUR. Total gain: 36,375 EUR a year, excluding the cash flow benefit of invoicing clients on D+1. Payback: about 15 months after maintenance.
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FAQ
Do we need to change payroll software?
No. The custom module integrates with your current vendor, which keeps producing payslips and the DSN. You keep your 300 to 900 EUR monthly subscription and only add the timesheet and approval layer.
How much does e-signing assignment contracts cost?
Between 0.50 and 1.50 EUR per signature depending on provider and volume. For 150 contracts a week, budget 4,000 to 11,700 EUR a year, to compare with the risk of reclassification as a permanent contract.
Will client companies agree to approve online?
Yes, especially if approval takes one click from an email or SMS. Agencies that switch to a portal generally get over 90% of timesheets approved within 24 h by the second month.
Does the module handle several collective agreements?
Yes. The rules engine applies the premiums specific to each collective agreement and client deal (construction, transport, cleaning), which accounts for 5,000 to 10,000 EUR of the budget.
Can we start smaller?
Yes. A first phase with the temp app and payroll export costs 12,000 to 18,000 EUR excl. VAT and ships in 6 weeks. The client portal and invoicing follow later.
Let's scope your project. Send us your weekly temp volume, payroll vendor and main collective agreements, and we will price a 25,000 to 50,000 EUR module deliverable in 3 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.
