# The Merchant Shipping (International Safety Management (ISM) Code) Regulations 2026, Regulation 23: Prohibition on non-United Kingdom ships proceeding or attempting to proceed on any voyage without a relevant document


(1) An ISM company must not operate a non-United Kingdom ship in United Kingdom waters unless that company has been issued with a valid compliance document in relation to ships of that ship’s type.
(2) A non-United Kingdom ship must not proceed or attempt to proceed to sea or on any voyage from a port in the United Kingdom unless there is in force a valid certificate in respect of that ship.
(3) An ISM company must ensure that a copy of a compliance document which has been issued to that ISM company, and the certificate which has been issued in respect of a non-United Kingdom ship operated by that ISM company, is—
(a) held on board that ship; and
(b) readily available for inspection at all times.
(4) For the purposes of this regulation, a relevant document ceases to be valid if—
(a) it has been suspended or cancelled—
(i) in accordance with Part B of the ISM Code, in relation to a non-United Kingdom ship flying the flag of a Convention country; or
(ii) by the State which issued the relevant document, in relation to a non-United Kingdom ship flying the flag of a State which is not a Convention country;
(b) it does not display endorsements showing that satisfactory verifications have been carried out—
(i) in accordance with Part B of the ISM Code, in relation to a non-United Kingdom ship flying the flag of a Convention country; or
(ii) by the State which issued the relevant document, in relation to a non-United Kingdom ship flying the flag of a State which is not a Convention country; or
(c) the period of validity of that document, including any extension—
(i) in accordance with Part B of the ISM Code, in relation to a non-United Kingdom ship flying the flag of a Convention country; or
(ii) by the State which issued the relevant document, in relation to a non-United Kingdom ship flying the flag of a State which is not a Convention country,
has expired.
(5) In this regulation—
“certificate” means—
(a) in the case of non-United Kingdom ship flying the flag of a Convention country, a Safety Management Certificate or an Interim Safety Management Certificate—
(i) issued—
(aa) in accordance with Part B of the ISM Code; or
(bb) by the Secretary of State in respect of that ship in accordance with regulation 21(2)(b) (issue and enforcement of relevant documents on behalf of another Convention country); and
(ii) where appropriate, endorsed by the government of the relevant Convention country or by the Secretary of State; and
(b) in the case of a non-United Kingdom ship flying the flag of a State which is not a Convention country, a document which demonstrates, to the satisfaction of the Secretary of State, an equivalent level of compliance with each requirement of the ISM Code applicable to that ship;
“compliance document” means—
(a) in the case of a non-United Kingdom ship flying the flag of a Convention country, a Document of Compliance or an Interim Document of Compliance—
(i) issued—
(aa) in accordance with Part B of the ISM Code; or
(bb) issued by the Secretary of State in respect of that ship in accordance with regulation 21(2)(a); and
(ii) where appropriate, endorsed by the government of the relevant Convention country or by the Secretary of State; and
(b) in the case of a non-United Kingdom ship flying the flag of a State which is not a Convention country, a document which demonstrates, to the satisfaction of the Secretary of State, an equivalent level of compliance with each requirement of the ISM Code applicable to the ISM company which operates that ship; and
“relevant document” means a compliance document or a certificate.

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Source: https://www.legislation.gov.uk/uksi/2026/194/regulation/23 (the official version)
Page: https://openlegislation.uk/merchant-shipping-international-safety-management-ism-code-regulations-2026/regulation-23
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.