The Working Time Regulations 1998

Maximum weekly working time E+W+S

4.—(1)  [F1 Unless his employer has first obtained the worker’s agreement in writing to perform such work], a worker’s working time, including overtime, in any reference period which is applicable in his case shall not exceed an average of 48 hours for each seven days.

(2) An employer shall take all reasonable steps, in keeping with the need to protect the health and safety of workers, to ensure that the limit specified in paragraph (1) is complied with in the case of each worker employed by him in relation to whom it applies [F2 and shall keep up-to-date records of all workers who carry out work to which it does not apply by reason of the fact that the employer has obtained the worker’s agreement as mentioned in paragraph (1)].

(3) Subject to paragraphs (4) and (5) and any agreement under regulation 23(b), the reference periods which apply in the case of a worker are—

(a) where a relevant agreement provides for the application of this regulation in relation to successive periods of 17 weeks, each such period, or

(b) in any other case, any period of 17 weeks in the course of his employment.

(4) Where a worker has worked for his employer for less than 17 weeks, the reference period applicable in his case is the period that has elapsed since he started work for his employer.

(5) Paragraphs (3) and (4) shall apply to a worker who is excluded from the scope of certain provisions of these Regulations by regulation 21 as if for each reference to 17 weeks there were substituted a reference to 26 weeks.

(6) For the purposes of this regulation, a worker’s average working time for each seven days during a reference period shall be determined according to the formula—

where—A is the aggregate number of hours comprised in the worker’s working time during the course of the reference period;

B is the aggregate number of hours comprised in his working time during the course of the period beginning immediately after the end of the reference period and ending when the number of days in that subsequent period on which he has worked equals the number of excluded days during the reference period; and

C> is the number of weeks in the reference period.

(7) In paragraph (6), “excluded days" means days comprised in—

(a) any period of annual leave taken by the worker in exercise of his entitlement under regulation 13 [F3 , 13A or 15B];

(b) any period of sick leave taken by the worker;

(c) any period of maternity [F4 paternity, adoption or parental] leave taken by the worker; and

(d) any period in respect of which the limit specified in paragraph (1) did not apply in relation to the worker [F5 by reason of the fact that the employer has obtained the worker’s agreement as mentioned in paragraph (1)].

Textual Amendments

F1 Words in reg. 4(1) substituted (17.12.1999) by The Working Time Regulations 1999 (S.I. 1999/3372), regs. 1(1), 3(1)(a)

F2 Words in reg. 4(2) added (17.12.1999) by The Working Time Regulations 1999 (S.I. 1999/3372), regs. 1(1), 3(1)(b)

F3 Words in reg. 4(7)(a) inserted (1.1.2024) by The Employment Rights (Amendment, Revocation and Transitional Provision) Regulations 2023 (S.I. 2023/1426), regs. 1(2), 3(2)

F4 Words in reg. 4(7)(c) inserted (6.4.2003) by The Working Time (Amendment) Regulations 2002 (S.I. 2002/3128), regs. 1, 5

F5 Words in reg. 4(7)(d) substituted (17.12.1999) by The Working Time Regulations 1999 (S.I. 1999/3372), regs. 1(1), 3(1)(c)