The verdict in three sentences
For a bureau producing 4,500 payslips a month for 220 SMEs, a custom client extranet costs EUR 35,000 to 70,000 excl. VAT and ships in about four months. The payroll software connector (Silae, Sage Payroll, BrightPay or similar), at EUR 8,000 to 20,000, matters more to profitability than the portal design. With 1.5 to 3 FTEs of re-keying freed, payback usually lands between 12 and 24 months.
What a payroll extranet costs in 2026, item by item
The budget depends less on the number of screens than on business rules: checks on pay inputs, absence handling, client-side approval. Here is a realistic breakdown for a mid-sized bureau (2026 order of magnitude).
| Work package | Scope | 2026 range (EUR excl. VAT) |
|---|---|---|
| Discovery and mock-ups | Workshops, client and payroll officer journeys, clickable prototype | 4,000 - 8,000 |
| Pay input capture | Per-employee forms, consistency checks, Excel import | 9,000 - 18,000 |
| Supporting documents | Sick notes, expense claims, contracts, automatic filing | 5,000 - 10,000 |
| Payslip vault | Distribution to employees, long-term archiving via a certified provider | 6,000 - 12,000 |
| Security | Two-factor authentication, access log, encryption | 3,000 - 7,000 |
| Payroll officer dashboard | Close status per client, automatic reminders | 5,000 - 10,000 |
| Testing and go-live | QA, migration of 220 accounts, training | 3,000 - 5,000 |
| Extranet total | 35,000 - 70,000 | |
| Payroll software connector | API or import file exchange | 8,000 - 20,000 |
Two things move the bill. First, the depth of validation: checking that an employee on sick leave has no overtime entered costs a few days of development but prevents corrected payslips. Second, the vault: retention rules for electronic payslips are long (50 years in France, multi-year obligations in Ireland), so you should rely on an archiving provider rather than storing PDFs yourself.
For running costs, budget a market order of magnitude of EUR 150 to 400 a month for EU hosting and annual maintenance of 10 to 15% of the build cost.
Vendor portal or custom extranet
Payroll software vendors offer client and employee portals. They are often enough for a bureau running 1,000 payslips. At 4,500 payslips, the maths changes, especially if the bureau runs two payroll systems after acquiring a client book.
| Criterion | Vendor portal | Custom extranet |
|---|---|---|
| Upfront cost | EUR 0 to 10,000 of configuration | EUR 35,000 to 70,000 excl. VAT |
| Recurring cost | Per-payslip subscription, often EUR 0.50 to 1.50 (estimate) | Hosting and maintenance, EUR 8,000 to 14,000 a year |
| Annual cost at 4,500 payslips | EUR 27,000 to 81,000 | EUR 8,000 to 14,000 |
| Pay input checks | Vendor standard | Rules specific to the bureau and each client |
| Multiple payroll systems | No | Yes, one portal |
| Branding | Bureau logo | Fully branded experience |
| Set-up time | 2 to 6 weeks | 4 months |
The decisive line is the recurring cost: above 3,000 payslips a month, a per-payslip subscription quickly exceeds the depreciation of a tool you own. Below that, the vendor portal remains the rational choice.
Where the gain sits: re-keying
As long as pay inputs arrive by email, in Excel files that all look different, every payroll officer copies, checks and chases. The table below shows typical measurements for a bureau of this size before and after the extranet.
| Indicator | Before (email and Excel) | After extranet |
|---|---|---|
| Pay input handling per payslip | 6 min | 1.5 min |
| Re-keying hours per month | 450 h | 112 h |
| Full-time equivalent (151.67 h) | 3 FTE | 0.75 FTE |
| Month-end client chasing | 3 person-days | Automatic |
| Corrected payslips | 2 to 3% | Under 1% |
| Close time after receipt | D+4 | D+2 |
The net gain, around 2.2 FTEs, is rarely used to cut headcount: it lets the bureau absorb new clients without hiring, in a Dublin market where an experienced payroll specialist costs EUR 45,000 to 55,000 a year fully loaded.
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Mini case study
Siobhan, managing director of a 14-person payroll bureau in Dublin, picks an extranet at EUR 52,000 and a payroll connector at EUR 14,000, for EUR 66,000 excl. VAT. She frees 2.2 FTEs valued at EUR 48,000 each, or EUR 105,600 a year of capacity. Counting only one FTE actually redeployed to 40 new clients, the return is EUR 48,000 a year: payback in 16.5 months. If she also avoids a vendor subscription at EUR 0.80 per payslip (EUR 43,200 a year), payback drops below nine months.
FAQ
Is the payroll software connector essential?
Without it, payroll officers export and re-import files, which keeps 20 to 30% of the re-keying. The connector, at EUR 8,000 to 20,000 excl. VAT, turns the extranet into a genuinely automated chain.
How long does it take to onboard 220 clients?
Rolling out in waves of 40 clients takes 6 to 8 weeks after go-live. Plan a 30-minute webinar per wave and a one-page guide.
What GDPR obligations apply to sick notes?
They are special-category data: EU hosting, two-factor authentication, an access log and a defined retention period. A data processing agreement must be signed with each of the 220 clients.
Can we start with a smaller version?
Yes. A first release limited to pay input capture and document upload costs around EUR 25,000 to 35,000 excl. VAT and ships in 10 to 12 weeks.
What does the tool cost after launch?
As a market order of magnitude, EUR 150 to 400 a month of hosting and 10 to 15% of the initial budget per year for maintenance and regulatory updates.
Let's scope your project. Send us your payslip volume, your payroll software and your current pain points: we will scope the perimeter, indicative budget and delivery time. 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.
