As soon as the UK completes its separation from the EU, it will be treated as a third-country. At which point, Article 27 will start applying to all British companies meeting the criteria. Who are these businesses? Multinational corporations are almost certainly prepared and will have an office somewhere in the EU already. Medium-sized companies, however, are less likely to have local offices to cater to the needs of their EU customers. These businesses will quickly need to prepare for Article 27.