We conduct a structural gravity econometric analysis, evaluating the impact of the UK’s decision to exit the EU on trade in six groups of agricultural products (poultry, other meat, dairy, cereals, vegetables, and fruit) of British and French regions. Results indicate that the UK started restructuring its mix of suppliers and destination markets before the post-Brexit trade rules took effect in early 2020. Anticipating the increase in trade costs with the EU, the UK took advantage of its free trade with EU partners, increasing purchases from these suppliers (+19%) to the detriment of countries with which it had no trade agreement (-15%). At the same time, it reoriented its exports to these latter partners in reaction to the expected deterioration of its competitiveness on EU market. However, these results mask substantial heterogeneity across regions and products. England & Wales largely drives the impact at country level, while Scotland and Northern Ireland often feature opposite evolutions in imports and exports. Regional disparities are the strongest for trade with extra-EU countries in cereals, dairy, and non-poultry meat. Still, despite some large percentage changes, these opposite shifts correspond to quite small traded amounts. French regions’ trade with the UK was also heterogeneously affected. The strongest impacts are concentrated on their exports. The exports of crop products generally decline, while the exports of non-poultry meat and dairy products generally increase. Suppliers of animal products from a few top producing regions register important export gains: Bretagne for non-poultry meat, Normandie and Auvergne-Rhone-Alpes for dairy.