We are also a small US business with occassional sales to the UK. I’m trying to figure this out as well. I wish there was a guide with a checklist that we could use. I’m going to contact our CPA and see if they have any guidance to offer.
In our FAQs to international customers, we state they may be responsible for duties and related costs. However, the information I have read regarding VAT states that if the proper paperwork is not in place, we risk the package being sent back. I want to avoid any potential issues.