What do sequestration or seizure, mean on my account?

A SATD ("Saisie Avis à Tiers Détenteur" = Seizure Notice to Third Party Holder), a seizure or an administrative opposition (OA) allows the Public Treasury to get paid what you owe it, from your account. This may include: taxes, fines, canteen bills, hospitalization costs, etc.

Unfortunately, we are obliged to carry out their execution.

When your bank account is subject to seizure, a minimum amount is left in your account: the unseizable bank balance (Solde Bancaire Insaisissable in French). The amount varies regularly and is available on the Public Service website (in French).
So, if your balance is less than the unseizable bank balance, there is no seizure on your account.
If your balance is greater than the unseizable bank balance, we will seize the funds (up to the limit of the unseizable bank balance).