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How the US Post Office Works and What Services Are Available

By Constance Obi · Culture & Recreation Writer

What the US Post Office does and who runs it

The United States Postal Service (USPS) is a federal agency that delivers mail and packages to every address in the country, including rural areas where private carriers often do not go. USPS is independent from other government agencies—it does not receive tax dollars for operations, instead funding itself through postage sales and services. The Postmaster General, currently appointed by the USPS Board of Governors, oversees the entire system.

USPS operates roughly 31,000 post offices nationwide, including full-service locations, community post offices inside retail stores, and contract postal units run by private businesses. In South Carolina, you will find post offices in every county, from downtown Charleston to small towns in the Lowcountry and Upstate. Each location offers the same core services, though hours and staffing vary by size and location.

Key Takeaways

  • USPS delivers mail and packages to all US addresses six days a week, including rural locations that private carriers skip.
  • You can buy postage, mail packages, and access services like money orders and passport photos at any post office or online through USPS.com.
  • Shipping costs depend on weight, distance, and speed—Priority Mail reaches most addresses in one to three days, while First-Class Mail takes longer and costs less.
  • Post offices in South Carolina are open Monday through Friday and Saturday mornings, though hours differ by location; call ahead or check online before visiting.
  • USPS offers tracking for most packages and mail forwarding if you move, both available through your local post office or online.

Finding a post office near you and checking hours

The USPS website includes a post office locator tool at usps.com where you enter your address or zip code and see all nearby locations, their hours, and services offered. Each listing shows whether that office offers passport services, notary, or other specialized services. You can also call 1-800-ASK-USPS (1-800-275-8777) to speak with someone who can direct you to the nearest location.

Most full-service post offices in South Carolina operate Monday through Friday from 9 a.m. to 5 p.m., with Saturday hours typically from 9 a.m. to 1 p.m. Smaller offices and contract locations may have shorter hours or close for lunch. Holiday schedules vary—USPS observes federal holidays and may close or run limited hours. Calling ahead or checking the website saves a trip if you need a specific service or have questions about timing.

Mailing letters and packages: services and costs

USPS offers several mailing options depending on speed and budget. First-Class Mail is the standard option for letters and small packages under 13 ounces; it typically arrives within one to three business days and costs less than faster services. Priority Mail guarantees delivery in one to three days and includes tracking and insurance up to $100 at no extra charge. Priority Mail Express is the fastest option, delivering overnight or by 2 p.m. the next day, and includes up to $100 insurance.

For heavier items or when cost matters most, Media Mail is slower but cheaper for books, educational materials, and DVDs. Ground Advantage (formerly Parcel Select) is the slowest and least expensive option for packages, taking two to eight business days. Postage rates change periodically and depend on weight and distance. You can purchase postage at any post office, print it at home through USPS.com, or use a postage meter if you mail frequently.

Tracking packages and mail forwarding

Most USPS packages come with tracking at no extra cost. When you mail a package using Priority Mail, Priority Mail Express, or certain other services, you receive a tracking number that you can enter on USPS.com to see delivery status and estimated arrival. First-Class Mail packages also include tracking, though letters sent via First-Class Mail do not. You can sign up for Informed Delivery on USPS.com to receive daily emails showing which mail and packages are coming to your address.

If you move within South Carolina or out of state, USPS offers mail forwarding through the Change of Address service. You can file a change of address online at usps.com, by mail using Form 3575, or in person at any post office. The service typically costs around $1.10 for a temporary forward (up to 12 months) or a permanent forward, though prices may vary. Mail forwarding takes three to five business days to activate, so submit your request before you move if possible.

Additional services: money orders, passport photos, and notary

Post offices sell domestic and international money orders, which work like checks and can be mailed safely or cashed at banks and retailers. Money orders cost a few dollars depending on the amount and are useful for paying bills by mail or sending cash without risk. You need to show ID to purchase a money order.

Many post offices offer passport photo services for a small fee—typically around $15 for two photos. The photos meet State Department requirements and are ready the same day. Not all locations offer this service, so check the post office locator on USPS.com or call ahead. Some post offices also provide notary services, though availability varies by location. Call your local post office to confirm whether notary is available and whether you need an appointment.

Shipping internationally and customs

USPS ships packages and letters to more than 220 countries and territories. First-Class Package International Service is the most affordable option for small packages under four pounds, typically taking one to four weeks depending on the destination. Priority Mail International is faster, usually arriving in six to ten business days, and includes tracking and insurance. Priority Mail Express International is the fastest option, with delivery in three to five business days to most countries.

When shipping internationally, you must complete a customs form (either a green label or online through USPS.com) that describes the contents and declares the value. The form helps customs officials in the destination country process the package. Certain items cannot be mailed internationally—including liquids, aerosols, and some electronics—so check USPS.com or ask at the post office before shipping. Postage costs vary widely by destination and weight, so weigh your package and know where it is going before you visit.

Frequently Asked Questions

Can I buy postage online and print it at home?

Yes. You can purchase and print postage through USPS.com for Priority Mail, Priority Mail Express, and other services. You print the label at home, attach it to your package, and drop it in a mailbox or at the post office. Some services require you to drop packages at the post office rather than a mailbox.

What happens if my package does not arrive on time?

USPS does not may provide delivery dates for most services except Priority Mail Express, which includes a money-back may provide if it arrives late. For other services, you can file a claim through USPS.com or at your local post office if a package is lost or significantly delayed. You will need the tracking number and proof of value.

How long does mail forwarding take to start?

Mail forwarding typically begins three to five business days after you submit your change of address request. If you submit online or in person, it processes faster than by mail. Submit your request at least a week before you move to avoid missing important mail during the transition.

Do I need an appointment to use post office services?

Most services do not require an appointment—you can walk in during business hours. However, passport photo services and notary may require an appointment at some locations. Call ahead to confirm, especially if you need a specific service or are visiting during busy times like lunch or early morning.

Can I return packages to the sender through USPS?

Yes. If you receive a package you do not want, you can refuse delivery or return it. Write "Return to Sender" on the package and leave it for your mail carrier, or take it to the post office. The original sender may be charged a return fee depending on the service they used.