Recently if you are not a uk citizen and you travel with items worth more than 390 pounds you have to declare them, I have read from few people that they have been stopped and their items have been checked, someone paid 20% tax on items from paris. I find this unfair as some are trying to use the Brexit to benefit from. When i read the law on imported items to the uk for tourist if it is made in the eu then you pay 0%, but as people dont know the law and most of them are scared to be banned from entering the uk so they do pay without consulting the embassy or a lawyer.