The UK's decision to leave the EU in 2016 led to uncertainty in trade agreements. This study looked at how this uncertainty affected UK firms' decisions to export to the EU. By analyzing UK export data, the researchers found that over 5300 firms didn't start exporting to the EU, and over 5400 stopped exporting to the EU in 2016 due to trade policy uncertainty. If this uncertainty hadn't existed, 5.0% more firms would have started exporting, while 6.1% fewer firms would have stopped exporting to the EU.