The unpaid seller may exercise his right of stoppage in transitu either by obtaining actual possession of the goods or by giving notice of his claim to the carrier or other bailee in whose possession the goods are. Such notice may be given either to the person in actual possession of the goods or to his principal. In the latter case the notice, to be effectual, must be given at such time and under such circumstances that the principal, by the exercise of reasonable diligence, may prevent a delivery to the buyer.
When notice of stoppage in transitu is given by the seller to the carrier, or other bailee in possession of the goods, he must redeliver the goods to, or according to the directions of, the seller. The expenses of such delivery must be borne by the seller. If, however, a negotiable document of title representing the goods has been issued by the carrier or other bailee, he shall not be obliged to deliver or justified in delivering the goods to the seller unless such document is first surrendered for cancellation. (n)