Some countries allow related companies or those with certain financial, economic and organizational links to register as a single taxable entity – a VAT group or GST group. Depending upon the tax laws of the particular country, this may mean that you don't need to account for VAT/GST on goods and services supplied between group members.
To create a VAT/GST tax group:
Make sure that all companies in the group have the same Tax Registration Number and Tax Country Code.
Select the VAT/GST Group checkbox on all companies in the group.
Make sure that all accounts have the same Tax Registration Number and Tax Country Code as defined at company-level.
Create a tax code with a zero rate and use it as the Output VAT/GST Code on all customer accounts.
Create a tax code with a zero rate and use it as the Input VAT/GST Code on all vendor accounts.
See About Tax for the effect of this on VAT/GST tax calculations.