Issues with VAT in Purchasing and Payables

Hello

Our company receives price list from customers including VAT.
While inserting the price in the purchase orders it already includes VAT.
If we make a receipt the system creates a transaction to the amount specified in the purchase order.
We need this accounting transaction is not included to the VAT amount.
For example
Here's how the system works at the moment:
VAT = 13%

Purchase order
Item1 1000

Accounting for Receipt (Item1)
Dr Receiving Inventory 1000
Cr AP Accrual 1000

Accounting for Account Payable Invoice (Item1)
Dr AP Accrual 1000
Dr VAT 130
Cr Payables 1130

We need as following:
VAT = 13%

Purchase order
Item1 1000

Accounting for Receipt (Item1)