SUPPLY OF GOODS FROM DZ TO MAINLAND ON DDP TERMS

Hi

i have following query, would appreciate guidence from experts:

Since we are located in RAK FREEZONE (DZ) and we have several customers in UAE Mainland, when we supply goods we need to pass RAK Customs and none of our customer is registered with RAK Customs hence our Importer code is utilized for goods clearance.

Now due to this process all our sales transactions to mainland, imports get auto populated in our TRN box 6 “goods imported into the UAE” .

Previously per advice of our VAT consultants while submitting our returns we adjust such amounts in box 7 “adjustment to goods imported into the UAE”, considering these are not our imports and reflecting to our TRN only, since our importer code is used. At the same time we issue VAT RCM statements to customers informing them to do same treatment in their returns 

 is this correct?

our terms to customers are DDP basis  should we issue TAX invoice adding 5% VAT or treat these adjustments in box 10 “Supplies subject to reverse charge provisions” and not in box 7.

Thanks