FOI reference: FOI-2025-3168
You asked
Interested in the statistics of percentage of first cousin marriages in the UK.
We said
Thank you for your freedom of information request.
We do not collect data on marriages between first cousins.
Our marriage statistics are derived from information recorded when marriages are registered as part of civil registration, which is a legal requirement.
You can get married or form a civil partnership in England or Wales if you're 18 or over, not already married or in a civil partnership and not closely related.
However, NHS England does collect data on consanguineous relationships in its maternity services and may be better placed to help.