Field help (FASVAT) 

VAT code to which the asset is submitted. The tax code defines the rate, rules and terms for the deduction applicable to the operation.
If the creation of the fixed asset record takes place before the recording of the purchase in accounting, it is initialized with a tax code deducted from the tax rule associated to the BP. Based on the context, it is necessary to verify that this tax code corresponds to the tax actually applicable, or it should be modified.
A contextual menu suggests the "tax entry" option. It is possible to specify the taxes other than the VAT (additional/special taxes) likely to be assigned to the VAT calculation and therefore the Tax-incl amount.
This screen is also used to define which part of the tax amount is deductible.
The Tax-incl amount is calculated according to the chosen taxes.