The verdict in three sentences
For a 260-employee company spread across several sites in Dublin, manually re-keying payroll variables costs about 3 days of HR time per month and drives most payslip errors. An HRIS, time clock, expenses and payroll integration project costs EUR 10,000 to 30,000 excl. VAT in 2026, with automatic anomaly checks before the payroll run. The expected return is concrete: 4% fewer payroll errors, reliable PAYE submissions to Revenue and a close brought forward by 2 working days.
Where the 3 days of payroll work go
In a multi-site company, variables arrive through four channels: absences and leave approved in the HRIS, hours from time clocks (often a different system per site), bonuses entered by managers in spreadsheets, and expenses reimbursed through a dedicated tool. The payroll officer consolidates everything by hand, checks it, then re-keys it into the payroll software. Every transfer is a chance for error: a wrongly mapped absence code, a forgotten bonus, overtime counted twice.
| Variable flow | Monthly volume (260 staff) | Manual processing time | Observed error rate |
|---|---|---|---|
| Absences and leave (HRIS) | 180 to 250 lines | 6 h | 2 to 3% |
| Hours and premiums (time clocks, 3 sites) | 5,500 punches | 8 h | 3 to 5% |
| Variable bonuses (manager spreadsheets) | 90 to 140 lines | 4 h | 4 to 6% |
| Expense claims | 220 to 300 claims | 3 h | 1 to 2% |
| Pre-run checks and corrections | 260 payslips | 3 h | n/a |
| Total | 24 h, i.e. 3 days | about 6% of payslips affected |
These figures are 2026 orders of magnitude seen in companies of 200 to 300 employees. A payroll error rarely costs much in euros, but it costs trust, corrections the following month and compliance risk if the payroll submission to Revenue carries inconsistent data.
What a payroll and HRIS integration project includes
The goal is to remove re-keying, not to replace software. Market vendors (Sage, BrightPay, Thesaurus, ADP, Personio, HiBob, Kelio) almost all expose APIs or standard imports. The work consists of building reliable connectors, a code mapping table (absences, bonus elements, overtime premiums) and a rules engine that blocks anomalies before they reach the payslip.
| Project component | Content | 2026 budget (EUR excl. VAT) | Timeline |
|---|---|---|---|
| Scoping and flow mapping | Inventory of pay elements, codes, rules per agreement | 1,500 to 3,500 | 1 to 2 weeks |
| HRIS to payroll connector | Absences, starters, leavers, contract changes | 2,500 to 6,000 | 2 to 3 weeks |
| Multi-site time clock connector | Punch aggregation, premium calculation | 2,500 to 7,000 | 2 to 4 weeks |
| Bonuses via manager form | Structured entry, line manager approval, payroll export | 1,500 to 4,500 | 2 weeks |
| Expenses to payroll and accounting | Reimbursements, mileage, journal entries | 1,000 to 3,500 | 1 to 2 weeks |
| Anomaly rules engine | 30 to 60 rules: gaps, duplicates, caps, submission consistency | 1,000 to 5,500 | 2 to 3 weeks |
| Total project | 10,000 to 30,000 | 8 to 14 weeks |
Add EUR 150 to 500 excl. VAT per month for connector maintenance and hosting. The low end matches a single time clock system and documented APIs; the high end, three heterogeneous systems and complex overtime agreements.
Reliable submissions and compliance: what to lock down
Under PAYE Modernisation, every pay run is reported to Revenue in real time. If the input variables are right, the submission is right too. The rules engine checks consistency between sick leave recorded in the HRIS and illness benefit adjustments, start and leave dates, and allowance amounts. On GDPR, connectors only handle the data they need, with access logging and hosting in Ireland or the EU. Health data (reasons for absence) stays in the HRIS and never travels in clear text.
Mini case study
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Aoife, HR manager of a 260-employee services company spread across three sites in Dublin, Swords and Tallaght, launches a EUR 22,000 project. Before: 24 hours of re-keying per month, or 288 hours a year. At a loaded cost of EUR 42 per hour, that is about EUR 12,100 a year, plus 4 monthly hours of corrections (EUR 2,000 a year). After integration, 5 hours of checks remain each month. The annual gain is about EUR 11,600, minus EUR 3,600 of maintenance, or EUR 8,000 net. The project pays back in just under 3 years on time savings alone, and much faster once you count the 2-day earlier close and the drop from 6% to 2% of payslips affected by an error.
FAQ
Do we need to change payroll software to automate?
No, in 8 cases out of 10 existing software has an API or standard import. The project connects the tools in place, avoiding a payroll migration that often costs more than EUR 40,000.
How long does the project take?
Allow 8 to 14 weeks, with at least 1 month of parallel running (old and new process). Go-live ideally happens at the start of a quarter.
What if a vendor changes its API?
Monthly maintenance (EUR 150 to 500) covers connector monitoring and updates. An alert is sent within 24 h if a flow fails.
Do managers have to change their habits?
Yes for bonuses: the spreadsheet is replaced by an online form with approval. Training takes about 30 minutes per manager.
Does it make sense under 100 employees?
It is rarely profitable below 80 employees on a single site. Above 150 employees, or from 2 sites with time clocks, the return usually exceeds the cost within 3 years.
Let's scope your project. Send us your HR and payroll software list, number of sites and headcount: we price the connectors within EUR 10,000 to 30,000 excl. VAT with an 8 to 14 week plan. 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.