This study investigates the impact of Brexit uncertainty on the UK's services sector trade from 2016 to 2019 revealing a statistically significant negative impact that varied across sectors and destinations. Using the OECD-WTO Balanced Trade in Services dataset and synthetic difference in differences methodology, the findings indicate an annual shortfall of US$23.7/£18.5 billion in UK services exports compared to a scenario where the UK remained in the EU, translating to a 5.65 percent reduction. The bilateral data suggests an 8.5 percent average decline, with larger exports to countries like Germany and the US being less affected than smaller bilateral exports. The UK bilateral exports to the EU declined by 6.21 percent, while Ireland’s exports expanded by 21.4 percent. The study highlights that small firms were disproportionately impacted, leading to a decline in trade openness and export activities. Methodological sensitivity is underscored, with various approaches estimating Brexit’s impact differently. Sectoral analysis shows significant declines in Travel, Insurance, Finance, Telecom, Business and Cultural Services. Ireland notably benefited post-Brexit, experiencing a 14.75 percent annual increase in services exports due to business relocations. The study emphasizes the critical yet underexplored consequences of economic disintegration on international trade in services, providing essential evidence for future UK-EU trade relations post-Brexit.