A mail carrier sorts and delivers mail for the United States Postal Service (USPS) which is owned by the US government. A mail carrier is a government employee who directly serves the public. Persons wanting to become a mail carrier must apply at their local post office as the USPS does not use a centralized location for job applications.

The local post office will supply the applicant with available dates and times for the USPS Exam 473. The USPS Exam 473 is a standardized test that all prospective mail carriers must pass and it tests memory and reading ability. Test scores are ranked and those with the highest scores are the first chosen to be mail carriers. Competition is steep, but one can take the test more than once and only the highest score is compared with the others. Practice tests are located in most libraries and/or one can ask at the post office for pamphlet "60-A Test 473 Orientation Guide for all Major Entry Level Jobs" that includes examples of questions on the exam.

In order to become a mail carrier, the applicant must be 18 or older and a US citizen or have a permanent resident alien status. One must also pass a physical examination and have a current valid driver's license. A dependable, honest nature is necessary as a mail carrier is considered responsible for the delivery of mail and in communicating efficiently with the public. One must be able to work well under pressure as sometimes there can be a high volume of mail to deliver. A good physical condition is important as one may be walking several miles every day in all types of weather conditions.

One must be prepared to not only deliver the mail, but sort and bundle it first. Most mail carriers start at 7AM and spend a few hours sorting mail in the post office before walking and delivering mail for the rest of the day. Overtime is sometimes required. Most mail carriers deliver by vehicle and on foot. A mail carrier in a city may be provided with a vehicle, but a mail carrier working in a rural area will likely have to have his or her own delivery vehicle.

Since the competition to become a mail carrier is an issue, be prepared to be on a waiting list for even a year or two. Speak to the local post office staff or postmaster about their waiting list. A USPS mail carrier usually must start in a part-time flexible (PTF) capacity. One may have to work PTF anywhere from a few weeks to a few years until a full time 40 hour work week becomes available. If a mail carrier must work on a Saturday, he or she will be given another weekday off instead.