The Brexit referendum was an important turning point for economic migrants in the UK, especially those from EU countries. Although many studies have focused on the general consequences of Brexit for migration, there is a noticeable gap in comparative research concerning economic migrants living in the UK. The chapter aims to analyze the motives for staying in the UK reported by Bulgarians and Poles (n = 980), to compare them with the original motives for migrating, and to contribute to the understanding of how these motivations changed in the context of Brexit. One of the methods used was the Classification and Regression Tree (CART) technique for the identification of factors influencing the decision to stay in the UK post-Brexit. The study also included a hierarchical comparative analysis. Although for both national groups an important motive for remaining in the UK was economic issues, Bulgarians focused on job opportunities, while Poles concentrated on personal growth and professional advancement. The results lead to significant conclusions regarding the dynamics of migration motives in the context of Brexit, highlighting the need for more research on the differences between specific national groups of migrants in the UK.