How security companies can work out what unplanned overtime really costs: the formula, a worked example, the costs it misses and how to bring it down.
Category: Operations · Published: 2026-10-07
Overtime comes with running guarding around the clock. Unplanned overtime is different: late reliefs, no-shows and shifts covered by whoever is still on site quietly eat the margin on fixed-price contracts. This guide shows how to put a number on it using your own figures.
Planned overtime is built into the rota and the contract price. Unplanned overtime is the extra hours nobody approved in advance: an officer staying on because their relief didn't arrive, a double shift to cover a call-off, a late finish nobody noticed until payroll. That's the overtime worth measuring, because it's the overtime you can reduce.
Monthly unplanned overtime cost = unplanned overtime hours per officer per month × number of officers × hourly pay rate × overtime multiplier.
The multiplier depends on your contracts and where you operate. In the UK there's no legal overtime premium, so many guarding firms pay overtime at the normal rate, as long as average pay across all hours stays above the National Minimum Wage. In the US, the Fair Labor Standards Act requires time and a half for non-exempt employees over 40 hours a week, and some states, such as California, also have daily overtime rules.
Take a company with 40 officers who each average 4 hours of unplanned overtime a month, paid £13 an hour at the normal rate. That's 4 × 40 × £13 = £2,080 a month, or £24,960 a year. Paid at time and a half, the same hours cost £3,120 a month.
These are illustrative figures. Run the same formula on your own numbers: even a small number of hours per officer adds up across a workforce.
The wage bill is only the visible part. Unplanned overtime also brings:
Most unplanned overtime starts with a late or missing book-on that nobody saw in time. The fixes are mostly about visibility:
Pulcify's free guarding cost calculator runs this formula on your own figures, alongside rota admin time, unbilled hours and last-minute cover premiums, and shows what's left after Pulcify's price. No sign-up is needed.
No. UK law doesn't require an overtime premium, but average pay across all hours worked must not fall below the National Minimum Wage, and many contracts set their own overtime rates.
Multiply the unplanned overtime hours per officer by the number of officers, the hourly pay rate and any overtime multiplier. Pulcify's free guarding cost calculator does this for you.
Hours worked beyond the published rota that weren't approved in advance, such as covering for a late relief or a no-show.
Make book-ons and late starts visible as they happen, fill at-risk shifts from available officers nearby, and review overtime by site so the causes are fixed, not just paid.
Pulcify turns the checks described above into an automated workflow: licence and vetting status tracked per operative, expiry alerts before anything lapses, and audit-ready evidence packs generated on demand.
Start the Free plan (up to 20 employees, 2 sites and 2 admin accounts, no credit card), see pricing or book a demo.