Founded in 1986, San José Promesas only started to have a senior team in 2004. On 21 June 2016, the club was integrated into the structure of Extremadura UD and became its reserve team.[1] With the aim to respect its history, the club would be named also as Extremadura-San José and will continue wearing its classic mauve kit. In the following season, the reserve team was renamed to Extremadura B.