https://www.badmintonengland.co.uk/about-us/equality-diversity/
'Recreational activity 1. Badminton England encourages transgender and non-binary players to play badminton recreationally in the gender they identify as. This includes all recreational participation, including No Strings Badminton, and club night activity'
...
'Unsanctioned and sanctioned competition 3. Unsanctioned competition comprises of local tournaments and league play. It also includes Tier 5 (social) competition and events staged for players in education (e.g., primary school, secondary school, further education and higher education). 4. Sanctioned competition includes Badminton England sanctioned tournaments, national championships, the National Badminton League and county events where players are selected to represent their county, including county restricted events. 5. Competition at these levels has the potential to enable players to secure ranking points and/or representation at county level or higher. Therefore, fairness of competition will be prioritised. This requires competition at these levels (unsanctioned and sanctioned) to be categorised as:
• Female competition – players assigned female at birth
• Open competition – all individuals will be eligible to compete in the open category. This will replace the men’s category.'