How does the VAT treatment work for supplies made between offices that are spread across the Designated Zones and the mainland UAE?

A main office or branch office located in a Designated Zone may supply goods to a main office or branch office located in the mainland UAE. Such supplies are considered to be intra-entity supplies and are therefore outside the scope of VAT. However, there are cases where the companies belong to the same tax group, and the supplies are made from a branch office in a Designated Zone to the head office in the mainland UAE. This type of supply will be considered as importation of goods and will be subject to import VAT, if different custom codes are used in the documents by the office located in Designated Zone, and the office located in mainland UAE . 

Unregistered entities will have to pay import VAT before the goods are moved from the Designated Zone.