On pricing page
The prices displayed on the Pricing page of Sendinblue website exclude taxes.
On checkout page
After you've defined your plan and customized your offer, you will find the Checkout page.
In the Cost section, the prices are detailed. You can see precisely the net price and the taxes of your final invoice.
To know what VAT number you should fill and if it applies to you, please check Where can I add my VAT (TVA) number and Is VAT charged ?