If your workers need to drive in a country outside the UK, both you and they need to be fully aware of differences in laws and driver and vehicle requirements in all countries that will or might be passed through. Great Britain (GB) and Northern Ireland (NI) driving licences are valid in all European Union (EU) and European Economic Area (EEA) countries, but the differences in regulations will still need to be checked.
As for bringing a vehicle into the UK, there’s a set of actions that need to be completed, including notification, checks, registration, tax and insurance. If this isn’t done, either by the driver, fleet operator, trader or a contracted importer, relevant parties can be prosecuted.
Regarding the UK’s withdrawal from the EU
At the time of writing, the UK hasn’t yet left the EU and it’s unclear what changes will be made (if any) to requirements for UK vehicles or drivers in EU and/or EEA countries as a consequence of withdrawal. Consequently, check the step-by-step guide to driving abroad on GOV.UK before departing as the guidance on this page may no longer be correct (although we’ll endeavour to update it as soon as possible).