Hi demetrius,
Anything posted or couriered to you from another country goes through customs to check it is not banned or restricted and you pay the right tax and ‘duty’ on it.
The parcel or courier company (for example, Royal Mail or Parcelforce) is responsible for taking goods through UK customs.
You will not have to pay anything to the delivery company to receive goods worth less than £135 unless they’re gifts over £39 or excise goods (for example, alcohol and tobacco).
More information on below link:
Tax and customs for goods sent from abroad
Thank you.