As a general rule, as long as the marriage is recognised under local law, it ought to be accepted for all administrative purposes in the U.K. To seek full legal advice on this issue however, we recommend you speak to a solicitor trained in UK marriage legislation.

If you intend to have your Brazilian marriage ready to register in the UK you should: 

1. Translate your Brazilian marriage certificate at a sworn translator.
2. Legalise the translation at the nearest British Embassy, Consulate or Honorary Consulate.