Customs clearance is a necessary procedure in permitting goods that are transported to a country through an authorized customs broker.
It's intricate to perceive customers buying pattern, you never know when a foreign customer may admire your product and order it.
This will then be declared in the tax lines of your C88 by your UK customs clearance agent.
The clue is that the numbers end GB, meaning that they will be posted in the UK.
Keeping calm is part of the battle, try not to stress too much about the delays, your shipment will come eventually.
Customs duties ensure that there is a balance between the economies of different countries.