Rest periods, the opt-out and regulation 21(c): what your rota has to show

The 48-hour week, daily and weekly rest, and rest breaks are settled law under the Working Time Regulations 1998 — not something awaiting a future date. This page sets out what each rule requires, who can be exempted from the rest and break rules under regulation 21(c), and what compensates for that exemption when it applies.

Last reviewed 21 September 2026. Sources:the Working Time Regulations 1998,GOV.UK, andAcas guidance.

The rest and working-time entitlements

These apply to workers generally. The regulation 21(c) exemption below changes which of these a particular worker is entitled to — it does not remove all of them.

  • 48-hour average working week

    A worker must not work more than an average of 48 hours a week, normally averaged over a 17-week reference period, unless they have agreed in writing to opt out.

    Source

  • Daily rest

    Workers have the right to 11 consecutive hours of rest in any 24-hour period — if a shift ends at 8pm, the next one should not start before 7am.

    Source

  • Weekly rest

    An uninterrupted 24 hours off in every 7-day period, or 48 hours off in every 14-day period.

    Source

  • Rest breaks during a shift

    An uninterrupted 20-minute break during any working day longer than 6 hours. Whether it is paid depends on the contract, not the Regulations.

    Source

The 48-hour opt-out

A worker can agree in writing to work more than the 48-hour average. The agreement is voluntary — an employer must not pressure a worker into signing one, or penalise them for refusing. A worker can cancel it by giving written notice: at least 7 days unless the agreement sets a longer notice period, which cannot exceed 3 months. Opting out of the 48-hour limit does not remove the daily rest, weekly rest or rest-break entitlements above — those are separate rights.

Source

Regulation 21(c): continuity of service or production

Regulation 21(c) of the Working Time Regulations 1998 lists sectors where work cannot reasonably be interrupted. The regulation's own wording, quoted directly:

"where the worker's activities involve the need for continuity of service or production, as may be the case in relation to— (i) services relating to the reception, treatment or care provided by hospitals or similar establishments (including the activities of doctors in training), residential institutions and prisons; (ii) work at docks or airports; (iii) press, radio, television, cinematographic production, postal and telecommunications services and civil protection services; (iv) gas, water and electricity production, transmission and distribution, household refuse collection and incineration; (v) industries in which work cannot be interrupted on technical grounds; (vi) research and development activities; (vii) agriculture; (viii) the carriage of passengers on regular urban transport services"

For these workers, regulation 21 removes the specific entitlements to daily rest, weekly rest and in-shift rest breaks set out above (and the length-of-night-work limit). It does not remove the 48-hour average weekly limit — that keeps applying regardless of sector.

Compensatory rest (regulation 24)

Where regulation 21 removes daily rest, weekly rest or a rest break, the employer must, wherever possible, allow an equivalent period of compensatory rest. Only where that is genuinely not possible for objective reasons may the employer instead give the worker other protection appropriate to safeguard their health and safety.

Source

Plain-English sector list: Acas — jobs with different working time rules.Regulation 21 on legislation.gov.uk.

What a rota needs to show

Whether or not regulation 21(c) applies to a role, the underlying question in a dispute or an inspection is the same: what hours were actually worked, when, and what rest fell between them. Where compensatory rest applies instead of the standard rest periods, the question becomes whether that compensatory rest was actually given.

Toi 'n' Moi® Rota Management records when each shift was published, worked, changed and cancelled, and keeps the history a rest-period or opt-out question would be checked against. It does not decide whether regulation 21(c) applies to a role, or calculate compensatory rest for you — it keeps the record that a manager, or an inspector, would need to check either.

Related

The Working Time Regulations are current law. The Employment Rights Act 2025's shift duties — guaranteed hours, reasonable notice, and payment for cancelled shifts — are a separate, later set of rights, not yet in force.Read what sections 1-3 of the Act will require, or see thefull Employment Rights Act 2025 timeline.

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