Although the U.S. Bureau of Consular affairs generally prohibits Americans from holding more than one passport at a time, there are exceptions to the rule, including those for frequent business travelers.
The first exception applies to U.S. citizens who would be denied entry to a certain country (or countries) if their passports show they’ve been to other countries.
For example, a passport holder with a visa stamp from Israel can be denied entry to several other countries; these include Syria, Lebanon, Libya, Kuwait, Iran, Iraq (except the northern Kurdish region), Sudan, and Yemen. Having a second passport without an Israeli visa stamp would enable him or her to travel to these other countries.
A second passport can also be issued for immediate travel when one’s original passport has been held up for foreign visa processing to another location. In this instance, the U.S. government would typically allow a second passport to be issued if the original passport wouldn’t be available in time.
According to the U.S. state department, second passports can also be provided to those who need multiple visas on a one-time or ongoing basis (for instance, flight attendants for international airlines, journalists, etc.)
Applying for a second passport is similar to the original passport application process, although there may be a couple of additional steps. These can include submitting a second passport request letter and, if applicable, a written statement from one’s employer.
It should also be noted that a second passport isn’t the same as a replacement passport. If the original passport has been lost, stolen, or is unavailable for any reason, the holder must submit a form for a lost passport and apply for a new one.