Permanent salaried staff

Salaried staff receive their contracted salary regardless of how many hours they work in any given week — up to their contracted limit. The calculation is straightforward: monthly salary paid monthly via payroll, with any overtime or additional hours handled per your company policy.

Where errors creep in for salaried staff: part-month adjustments for starters and leavers, statutory deductions during sick leave, and enhanced entitlements like company sick pay. Your payroll software should handle most of this, but it needs to be set up correctly for each contract type.

Zero-hours and casual hourly workers

Casual workers are paid for actual hours worked at their agreed hourly rate. This sounds simple but involves several moving parts:

The most common error with casual pay: Paying based on scheduled hours rather than actual hours. If a worker starts late or leaves early and you pay the scheduled shift, you are overpaying. If they stay longer and you pay the scheduled shift, you may be underpaying against NMW and creating wage claims. Always pay actual hours.

Different pay rates within the same team

A typical mixed team might include chefs paid at £15/hour, floor staff at £12.71, and kitchen porters at £12.71 — with different age bands and associated NMW minimums across the group. Managing this manually creates errors. Your payroll process needs to map each worker to their rate clearly, with the NMW minimum as a floor on each calculation.

Worker typePay basisHoliday methodCommon errors
Permanent salariedMonthly salary / contractDays recorded; pay unchangedPart-month calculations, sick pay
Zero-hours / casualActual hours x hourly rate52-week average OR 12.07% rolled-up (both lawful from Jan 2024)Scheduled vs actual hours; wrong method for worker type
Agency workersAgency invoice (per agreement)Agency responsibleAssuming agency handles NMW; no records

Agency workers

Agency workers are invoiced by the agency, not paid directly by you. The agency handles payroll, NMW, SSP, and holiday pay for their workers. Your cost is the invoice total — typically the worker's pay rate plus the agency's margin (usually 25–35%).

You do not calculate wages for agency workers, but you do need to keep records of their hours on your site for ERA 2025 compliance purposes — particularly for the guaranteed hours right coming in 2027. Track which agency workers work at your site, on which dates, and for how many hours.

Making the reconciliation manageable

Weekly wage reconciliation for a mixed team of 20+ workers is a significant time commitment if done manually. The businesses that handle it most efficiently are those where actual clock-in and clock-out data feeds directly into a wage calculation tool — eliminating the step where someone re-enters timesheet data into a spreadsheet.

FlexiWork's Wages module does this automatically. Every shift clocked through the platform produces a payroll-ready record, segmented by worker type and pay rate, that can go straight to your payroll provider. The manual reconciliation step largely disappears.

Automated wage calculation for mixed teams

FlexiWork calculates wages from actual hours, by worker type and rate. ERA 2025 records built simultaneously. 30-day free trial.

Start free — 30 days
No card required · 50% off early access pricing

FAQ

How do I calculate holiday pay for irregular hours workers? +
Use the 52-week reference period method. Take the worker's gross pay over the previous 52 weeks in which they worked and divide by the number of those weeks. That average is the weekly holiday pay rate. From 1 January 2024, rolled-up holiday pay at 12.07% per payslip is also explicitly lawful for genuine irregular hours workers. Both methods are compliant — choose one, apply it consistently, and keep records.
Do I need to pay overtime to zero-hours workers? +
Zero-hours workers do not typically have contractual overtime rates. Their pay is based on actual hours at their agreed rate. However, NMW must be paid for every hour worked, and WTR rest requirements apply regardless of contract type.
How does NMW apply to a mixed workforce? +
NMW applies uniformly to all worker types. The rate depends on age only. From 1 April 2026, NMW is £12.71 for workers aged 21 and over, £10.00 for 18–20 year olds, and £5.90 for apprentices and under-18s.