No, once a title is published with an ISBN on it, the ISBN can never be used again. Even if a title goes out of print, the ISBN cannot be reused since the title continues to be catalogued by libraries and traded by used booksellers.
The company being bought can have all its ISBNs transferred to the new owner. If the company is a subdivision or subsidiary of the new company, it can maintain its own unique ISBN prefix. If the company being bought is being demoted to an imprint (a brand) with no legal standing of its own, then the new parent company can use the ISBNs at will for any title it publishes.
ISBNs cannot be transferred on an individual basis. If a self-publisher wants to be identified as the publisher, the self-publisher must get their own ISBN. A printing company or publisher services company cannot sell, give away or transfer one of their ISBNs to a customer.
The publisher handling order fulfillment places their ISBN on the book. However, both publishers are entitled to put their ISBNs on the book in the case of a jointly published publication.
A new, unused ISBN must be assigned to the book, stickers or labels made and placed on the books, and all industry databases updated with the new, correct ISBN.
No. The ISBNs are considered property of the publishing company and the ISBNs can not be transferred to a friend or relative.
The ISBNs are considered property of the publishing company and all of the ISBNs can be transferred to the new owners, including a family member. The entire block of ISBNs is transferred to the new company owner(s). The block of ISBNs cannot be divided up among family members.
No, they do not have to be assigned, but they can be.
No, once a block of ISBNs has been used up, a new prefix (a new block) is assigned. It is mathematically impossible to add more numbers to a block.
Whoever is to be identified as the publisher obtains the ISBN. In most cases, the POD is the publisher and puts their ISBN on the book. In very rare cases, due to the contractual arrangements between the POD and the self-publisher, the self-publisher is the publisher. Most of the time, the POD is the publisher because the POD fulfills orders.
Yes, if a product needs to be tracked in the supply chain for trading, discovery, and reporting, it can be assigned a separate ISBN. Assessing distinctions between access rights programs for customers requires separate reporting.