The visible cost
Most companies count two items: the total employment cost of the payroll colleague and the annual licence fee of the payroll software. That figure is real but not complete — roughly in the way that the cost of running a car is not exhausted by the monthly instalment.
What gets left out of the comparison
In our experience these are the items most often missing:
- Training and keeping up with legislation. Annual training, professional subscriptions, conferences. This is not optional: the legal environment changes every year.
- Management time. How many hours a month go from the HR manager's and the finance director's time into payroll reconciliation, error-hunting and handling employee questions? That is often the most expensive hour of the first week of the month.
- The IT background. Server or cloud, backups, access management, data security measures. With pay data this cannot be skipped.
- The cost of errors. Not only a potential fine: corrective calculations, retrospective self-revision, loss of employee trust and the communication time spent on it all belong here.
- The price of missing documentation. If the knowledge sits in one person's head, the process does not exist in writing. The company receives that invoice on the day that person resigns.
The price of cover
This is the item least often quantified, yet it is the biggest risk. Ask yourself: what happens if the payroll colleague is out for two weeks from the third day of the month?
If the answer is "that would be very bad", then the company is not currently optimising cost — it is carrying risk, unpriced.
With an external provider, cover is part of the service. That does not mean outsourcing is automatically cheaper; it means this belongs on one side of the scales in the comparison.
How to calculate realistically
A simple framework
- Employment cost (pro rata for time spent on payroll, if the colleague does other work too)
- + software, licences, infrastructure
- + training, subscriptions, professional support
- + management time (hours × internal hourly cost)
- + estimated cost of errors (corrections, self-revision, potential penalties)
- + the price of cover risk (what would an urgent external solution cost?)
Set these six lines against twelve times the provider's monthly fee plus the one-off set-up fee. Now the two numbers are comparable.
Important: this calculation does not necessarily favour outsourcing. At smaller companies with simple pay structures the in-house solution often remains cheaper and faster. The goal is not to justify outsourcing but to base the decision on real numbers.
Summary
The cost of in-house payroll is spread out, so it looks understated. The provider's fee appears on one line, so it looks overstated. A good decision requires bringing both to the same denominator — and that takes no consultant, just an honest half hour with a spreadsheet.
