UK EWM works closely with the London Mathematical Society Women in Mathematics Committee, which among many other activities runs a Good Practice Scheme supporting mathematics departments interested in embedding equal opportunities for women. This serves as help and preparation for the British Athena award scheme for women in STEM. The Isaac Newton Institute also have a Gender Balance Programme.
The main meeting point is the annual Women in Mathematics Day. A four day event celebrating women across the mathematical sciences was held in Oxford in 2015 as part of the 150th anniversary year of the LMS. You can follow what is going on Twitter: @womeninmaths
A report written in 2011 can be found here.
Members of the London Mathematical Society can pay their EWM fees through the LMS.