personal seal; informal seal; unregistered seal
A personal, unregistered seal used for everyday informal purposes such as receiving parcels or internal documents, as opposed to a formally registered seal (実印) used for legal contracts. The term can also refer to the impression made by such a seal.
A personal seal is sufficient when receiving a parcel delivery.
You need a registered seal to open a bank account, but for everyday documents you use an informal seal.
Please stamp your personal seal to receive the delivery.
A personal seal is fine for this document.
Please bring your personal seal to the counter.