The governments top priority is to deliver a deal negotiated with the EU which would mean an implementation period until December 2020. This would give businesses time to prepare for any new relationship after we've left.
Every possible outcome including no deal is being prepared for by the government which means that without a deal you may need to take action sooner.
TVCA through the Tees Valley Business Compass has put together information and a Brexit Toolkit which will help you understand more about it and what you need to do for your business. You can access the information here.