You now have to match all your goods to commodity codes or faced blocked clearance and the wrong tax payments. (One way of avoiding these problems is to use Avalara's Cross-Border service.)
The relevant commodity codes are made up with a range of digits that identify a particular product. They specify the type of product, materials used and the production method as follows:
Goods sent abroad (not just to the EU but also to anywhere else) require a valid commodity or HS code to identify the duties payable and other shipping information. Not having a code, or using the incorrect code, can cause delays and even result in fines and/or confiscation and destruction of the shipment. These codes are available via HMRC.
For further details and for a full range of international codes, see also: Bank, Corporate, Industry & Product Codes.