To be clear if an agreement is struck and we continue to be part of the EU free trade zone nothing changes pending a proper deal to be agreed at a later date. However, if there is no agreements and we do leave the EU on schedule the country goes onto WTO terms which currently would mean an Import Duty of 2.7% (some say 2.8%).
It is unclear how this will effect deliveries immediately following March 27th but at least one manufacturer is indicating up to a 7 day additional delay to their deliveries and that this charge will be passed onto clients in full. It remains very uncertain of how this will be applied for contract bids in the future.