Objective: Find the pre-tax base from the VAT 1. Objective: Find the pre-tax base from the VAT When the invoice only indicates the VAT amount (for example, 19 D), without specifying the pre-tax (ET) base, it is possible to reconstruct this base using a simple mathematical formula, provided you know the VAT rate applied. This method is useful for accounting or tax audits. 2. Basic formula: VAT = Pre-tax base × VAT rate The basic formula is: VAT = Pre-tax base × VAT rate. Therefore, to find the pre-tax base, we reverse the formula: Pre-tax base = VAT ÷ VAT rate. For example, if the VAT is 19 D and the rate is 19%, then: Pre-tax base = 19 ÷ 0.19 = 100 D 3. Beware of confusion with the TTC amount This method should not be confused with the method that consists of finding the TTC amount (all taxes included). If you have the amount including tax and you want to find the base excluding tax, the formula becomes: Base excluding tax = including tax ÷ (1 + VAT rate) Example: Including tax = 119 D, VAT rate = 19% Base excluding tax = 119 ÷ 1.19 ≈ 100 D