Up until 29th August 2025, items entering the United States with a value of less than $800 were exempt from import duty. The discontinuation of the $800 de minimis exemption for all countries, means that ALL items are now subject to US import duty, irrespective of value. Duty on items from the United Kingdom is 10%.
Sadly, I have subsequently split my 'USA Canada' shipping rates. Prices to USA include import duty which I pay when I book the shipping. On the plus side, this speeds up delivery of items and there's nothing more for you to pay