The following are a few useful links to help you with buying & selling to/from the United Kingdom post Brexit and with any non-EU country.
1. https://intertradeireland.com/brexit/ - this is the Brexit section of InterTradeIreland’s website and contains a lot of great resources for businesses preparing for Brexit, including a tariff checker, details of upcoming Brexit events and guides to cross-border trade post-Brexit.
2. https://brexitandbeyond.intertradeireland.com/ - this is InterTradeIreland’s online learning tool, which goes through procedures etc. for exporting to / importing from a non-EU country and other Brexit related issues.
3. www.prepareforbrexit.com – this website from Enterprise Ireland includes great information on post-Brexit Ireland and how this might look. There is also a Custom’s insight course here that you should complete as part of your Brexit preparations.
4. http://tariffdata.wto.org/default.aspx - this resource allows you to go through all of the product codes for WTO tariffs and details on the tariffs on each product code.
5. https://www.revenue.ie/en/customs-traders-and-agents/brexit/brexit-background/index.aspx - this gives information on how your Revenue returns etc. will change post-Brexit.
6. https://www.revenue.ie/en/vat/goods-and-services-to-and-from-abroad/imports/when-is-vat-payable-on-importation.aspx - this gives information on how to appropriately account for VAT at Point of Entry to the EU.