Works that are not subject to copyright are in the public domain. They may be used without permission. In the United States, a copyrightable work is in the public domain if:
Every country has its own rules about when a copyrightable work enters the public domain.
In the United States today, copyright protection automatically covers all new copyrightable works. The moment the work is fixed in a tangible medium of expression, it is subject to copyright.
In the past, authors had to comply with certain formalities in order to obtain copyright protection. These formalities included registering the work with the US Copyright Office and placing a copyright notice on the work. Copyright law no longer requires that authors comply with these formalities merely to obtain copyright protection. However, registering a work and putting a copyright notice on a work still come with legal benefits, so authors often do these things anyway.
Under current US law, you do not have to provide a copyright notice on your work to receive copyright protection. However, if you are making your work publicly available, you may want to.
Putting a copyright notice (the copyright symbol (©), the year of publication, and the name of the copyright owner) on a work tells the rest of the world that the work is protected by copyright. If the copyright owner later sues someone for infringing her copyright in the work, she can point to the notice to show that the defendant is not an “innocent infringer” and thus may need to pay higher damages.
Under current US law, you do not have to register your work to receive copyright protection. You may want to register it anyway, because copyright registration comes with certain legal benefits. If the work is registered within three months of its publication date or before a particular infringement occurs, the copyright owner can recover statutory damages (monetary awards that need not be connected to actual harm suffered by the copyright holder) and attorney’s fees if she is successful in an infringement suit. Registration is also required before the author can bring a lawsuit about use of her work. However, because registration takes time and money, many works are never registered.
Registering a copyright is not difficult. For instructions and forms, visit the US Copyright Office website. If you have any questions regarding copyright registration, the US Copyright Office has a toll-free help line at 1-877-476-0778. You may register a work at any time while it is still in copyright.
Most works created in the United States today will be protected until 70 years after the death of their last surviving author. Other rules apply for certain works. For instance, if a work was created by the employee of a corporation acting within the scope of her employment, the copyright will last either 95 years after publication or 120 years after creation of the work, whichever results in a shorter term.
Before March 1, 1989, duration for published works was tied to compliance with formalities. Thus, publication date, publication status, registration, notice, and renewal all impact copyright duration. In addition, because of international treaty obligations, the nationality of the author(s) and the location of publication(s) can also impact duration. We recommend using Cornell's chart, Copyright Term and the Public Domain in the United States, and Berkeley's PDF handbook, Is it in the Public Domain?, to determine whether a particular work is in the public domain in the United States.
All works published in the United States before 1923 are in the public domain in the United States.
Prior to 1964, US law divided copyright terms into two parts: the initial term and the renewal term. At the end of the initial copyright term, the copyright holder would have to renew the copyright in order for the work to remain protected during the renewal term. If you are trying to determine whether the copyright in a work published before 1964 was renewed, consult the Stanford Copyright Renewal Database and the Catalog of Copyright Entries.