What is the difference between standby pay and on-call pay for National Minimum Wage purposes?

Full answer

Whether time spent on standby or on call counts as "working time" for National Minimum Wage purposes has been the subject of significant legal dispute, and getting the distinction wrong can result in employers underpaying workers without realising it. **The core legal distinction** The key test is broadly whether the worker is required to be at a specific place of the employer's choosing (making it much harder for them to use the time for their own purposes) or whether they are simply required to be reachable/available to respond if needed, but otherwise free to be wherever they choose and to pursue their own activities largely uninterrupted. Workers required to remain at or very near the workplace itself during standby (for example, sleeping at a care home in a designated on-site room specifically to respond to residents' needs) are more likely to have the WHOLE standby period counted as working time for minimum wage purposes, since their freedom to use the time for their own purposes is significantly restricted by the location requirement. **"Sleep-in" shifts -- a specific area of dispute** A particularly contentious area has involved care workers required to sleep overnight at a client's home or a care facility specifically to respond if needed, but who are otherwise permitted to sleep for the whole shift unless called upon -- following extensive litigation, the current position generally holds that such workers are only entitled to minimum wage for time they are actually AWAKE and WORKING (for example, actually responding to a resident's needs), not for the whole sleep-in period, provided suitable sleeping facilities are genuinely provided and the expectation is that the worker will sleep for most or all of the shift. **On-call time away from the workplace** Where a worker is on call but permitted to be at home (or anywhere else of their choosing) and is only required to respond within a reasonable time if contacted, the time spent simply being on call (but not actually working) generally does NOT count as working time for National Minimum Wage purposes, since the worker retains meaningful freedom to pursue their own activities during this period -- only the time actually spent responding to a call-out (including reasonable associated travel time, depending on the specific arrangement) counts as working time requiring at least minimum wage. **Contractual on-call/standby payments are separate from the minimum wage question** Many employers pay a separate, specific on-call or standby allowance (on top of normal pay for hours actually worked when called out) as a matter of contractual agreement, recognising the inconvenience of being on call even where this does not strictly count as "working time" for minimum wage purposes -- this is a matter of contractual negotiation between employer and worker, separate from (and can be more generous than) the strict minimum wage requirements around what counts as working time. **Why getting this wrong matters** Employers who incorrectly treat time that SHOULD count as working time (for example, requiring workers to remain at a specific location with genuinely restricted freedom) as merely "on call" and therefore unpaid can face minimum wage underpayment claims, back-pay liability, and potential enforcement action, since National Minimum Wage compliance is checked against the effective hourly rate across ALL time that legally counts as working time, not just the hours the employer chooses to formally record as "worked." **Worked example** A residential care worker is required to sleep overnight at the care home in a designated staff bedroom, waking only if a resident needs assistance, with suitable sleeping facilities genuinely provided. Under current rules, she is entitled to at least minimum wage only for the time she is actually awake and providing care during the night, not for the full overnight sleep-in period, provided the arrangement genuinely reflects an expectation that she will sleep for most of the shift. By contrast, a security guard required to remain alert and monitoring premises throughout an overnight shift (even if call-outs are infrequent) would likely need to be paid at least minimum wage for the ENTIRE shift, since they are not genuinely free to sleep or pursue their own activities throughout. **Practical tip** Employers using standby, on-call, or sleep-in arrangements should carefully assess exactly how much genuine freedom the worker retains during the period (location restrictions, ability to sleep or pursue their own activities, response time requirements) against current case law and HMRC minimum wage guidance, since this is a technical and frequently litigated area where getting the classification wrong can result in significant historic underpayment liability.

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