The Union will be recognised by the UK Home Office if the following conditions are met:
Marriage is considered valid in the state in which it was contracted;
The union fulfils all the requirements and laws of the country where it was concluded;
All prior marriages are permanently dissolved;
The laws in the visa applicant’s country of residence do not prevent the union from being recognised as valid.
It is also worth considering the requirements regarding age, ineligibility and divorce from previous spouses. But in most cases, if the country where your marriage was registered has recognised it as valid, the UK authorities will consider the union to be valid.