Rounding clock-in and clock-out times to the nearest 5, 6 or 15 minutes is common in UK payroll. It is not automatically unlawful.
What makes it lawful or not is whether it systematically pays you for less time than you actually worked.
The principle
There is no statute that says “rounding is permitted to the nearest X minutes”. What the law requires is that you are paid at least the minimum wage for all the time you work.
A rounding practice that cuts both ways — sometimes up, sometimes down, roughly balancing out — generally does not breach that, because across the pay reference period you are paid for the time worked.
A practice that only ever rounds down does breach it, because you are systematically paid for less time than you worked. “We round to the nearest 15 minutes” is defensible. “We round down to the nearest 15 minutes” is not.
Common increments
| Increment | Where it is used |
|---|---|
| 1 minute (exact) | Modern digital systems; always safe |
| 5 minutes | Common in retail and hospitality |
| 6 minutes | Professional services — gives tenths of an hour |
| 15 minutes | Traditional clock-card systems |
Six minutes exists because one tenth of an hour is convenient for billing. Fifteen minutes is a legacy of mechanical time clocks and is the increment most likely to cause noticeable discrepancies, since a worker can lose or gain up to 7.5 minutes per punch.
Our timesheet calculator defaults to exact minutes and offers rounding as an explicit option, because exact is always defensible and rounding never needs to be the default.
Where rounding becomes a real problem
Rounding the start up and the end down. Clocking in at 8:52 becomes 9:00, clocking out at 17:08 becomes 17:00. Sixteen minutes lost per day, over an hour a week, more than a full working week a year. This is not lawful and is a known enforcement target.
Rounding combined with a pay rate at the legal minimum. If you are paid exactly £12.71 an hour, any unpaid time takes your average below the minimum wage immediately. There is no headroom.
Waiting time being excluded. Time spent waiting to start, going through security, or on required handovers is generally working time and must be paid. Rounding is sometimes used to obscure this.
Rounding down to a whole hour. Rounding a 7 hour 50 minute shift to 7 hours is not rounding, it is a deduction.
Checking your own position
- Note your actual clock-in and clock-out times for two weeks.
- Total the actual minutes worked.
- Compare against the hours you were paid for.
- If the gap is consistently negative, you are being rounded down systematically.
- Divide your total pay by your actual hours. If that lands below the minimum wage for your age, that is a clear breach.
A small gap that sometimes favours you and sometimes does not is normal. A gap that always runs the same way is the problem.
If your hours are being rounded down
Raise it with your employer or payroll first. Rounding rules are often set up years earlier by someone who has since left, and a genuinely asymmetric rule is sometimes an oversight rather than a policy.
If that does not resolve it, HMRC enforces the minimum wage and you can report an employer confidentially. Employers found in breach must repay arrears at current rates, face penalties of up to 200% of the underpayment, and are publicly named — hundreds of employers of all sizes are named each year.
Acas offers free advice if you want to talk it through first.
For employers
If you are setting up a rounding rule, three points:
Round to nearest, never down. It is the only rule that is straightforwardly defensible.
Document it and tell staff. A rule nobody knows about looks like something being hidden.
Check the arithmetic on your lowest-paid staff. Anyone at or near the minimum wage has no buffer, and a rounding rule that is harmless for a salaried manager can put you in breach for a shift worker.
Honestly, exact minutes is easier than any of this. Every modern system supports it, and it removes the question entirely.
Sources
- National Minimum Wage rates — GOV.UK
- Calculating the minimum wage — GOV.UK
- Checking your pay — Acas
Checked against source on 30 August 2026. This is general guidance, not legal advice.
Written by Nathan Cole
I built the calculators on HoursHQ and check every statutory figure against GOV.UK, Acas and the legislation itself before it goes live. Where the law is genuinely unclear, I say so rather than guessing.