For marriages in the UK there is no requirement for Canadian citizens to obtain a certificate of non-impediment to marriage abroad or any other document from the Canadian High Commission.
If you are to get married elsewhere, please check the requirements with the authorities of the country concerned.
Certain countries do ask for a certificate of non-impediment to marriage issued by the Canadian authorities. The Canadian Government does not issue these certificates, but some countries may require a statement confirming that this is the case. This is called a statement in lieu of a certificate of non-impediment to marriage. Please contact the Canadian embassy in the country concerned in order to establish the requirements for Canadians getting married locally. The statement may have to be issued in that country in the national language. Please consult the list of Canadian embassies and consulates for email addresses and websites.
Please see the additional information provided under our entry for Notarial services.