TotalEnergies Aviation Card: Why request a guarantee? How is the amount calculated?

The TotalEnergies Aviation card is a credit card. The security deposit is designed to cover unpaid bills. The amount is calculated on the basis of estimated annual spending and is set at a minimum of €200. The deposit is refunded on the closure of your account. You may either pay the deposit or ask your bank to stand guarantor. In the latter case, you are responsible for making the necessary arrangements with your bank.