Problem: We are using tax groups for VAT and on final VAT calculation values differ from the detailed TAX reports.
Solution: The difference in Tax values (payable and receivable) in VAT Return Document and other Tax reports when Tax groups are due to changes in the tax groups used, to fix this the Tax groups members need to be updated each tax quarter.
Follow the steps to fix the issue.
1) . Go to Taxes>Master Data>Tax Groups:
2) . Open Tax group and go to to History section: 
3) . Create a new item. In :
- Period
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- - the tax quarter start date
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- Tax Group - select the tax group
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- Tax Group Members select the entities that are included in Tax group
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Press Save and Close:
4) Later you can . Next quarter, please use copy option and put the new period date only: 
5) After the changes have been done you need to . As changes are done, please refill the VAT Return document:
This report now will create creates the VAT return for the updated TAX groups Tax Group, and the total amount in VAT Return boxes will be equal to the total amount in detailed Tax Reports.
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# quarter update quarterly tax group issue