USPS tracking

American postal service created in 1775

The United States Postal Service (USPS) is the official postal service of the United States. It is an independent agency of the U.S. federal government, responsible for collecting, sorting, transporting, and delivering mail and packages across the country. Created in 1775, the USPS is one of the oldest operational postal services in the world. Its operation is guaranteed by U.S. legislation, which grants it a universal postal service mission: to deliver mail to the entire population over a vast territory, including rural and isolated areas, in a regular and reliable manner.

Since 1971, the USPS has operated as an autonomous entity of the executive branch, led by a Postmaster General and overseen by a Board of Governors. Although it is a public organization, it operates without direct taxpayer funding for its current operations, with its revenues primarily coming from the sale of stamps and postal services. With over 600,000 employees across the country, USPS is one of the largest civilian employers in the United States. Its mail carriers and sorting agents handle and deliver billions of items each year, ensuring a daily presence in the lives of American individuals and businesses.

Postal network and national coverage

The USPS network covers the entirety of the United States, including the 50 states, the District of Columbia (Washington D.C.), as well as U.S. territories such as Puerto Rico, Guam, the U.S. Virgin Islands, American Samoa, etc. USPS serves approximately 160 million addresses across these areas, whether they are households, businesses, or government offices. The postal service is historically committed to delivering mail six days a week (Monday through Saturday) across the entire national territory. In some urban areas or during periods of high volume, package deliveries may also be made on Sundays to ensure service continuity.

The internal organization of USPS is based on a dense network of local post offices and regional sorting centers. There are over 30,000 post offices and contact points across the country, ranging from large urban postal centers to small rural offices. For logistics, the country is divided into several postal regions and districts to manage operations more efficiently. Each region has processing and distribution centers responsible for centralizing incoming and outgoing mail. USPS also operates a specialized network for certain categories of addresses, including military addresses (APO/FPO) abroad, which allow mail to be sent to U.S. military bases worldwide as if it were domestic mail.

As an independent agency, USPS is managed by a board called the Board of Governors, composed of appointed members who oversee its strategy and finances, while the Postmaster General provides daily executive leadership. The organization is subject to the regulations of the Postal Regulatory Commission, which ensures compliance with universal service obligations and regulates certain rates. This governance structure aims to ensure that USPS fulfills its public service mission while maintaining economic viability and high service quality across the territory.

Varied range of postal services

USPS offers a very wide range of postal services to meet the needs of both individuals and businesses. These services cover the sending of letters, documents, and packages of various sizes, both nationally and internationally. Here are the main services offered:

• First-Class Mail: Basic service for sending letters, postcards, and small items. It is an economical and fast service within the United States for shipments weighing up to 13 ounces (approximately 368 grams). First-Class Mail receives priority handling over other non-urgent mail.
• USPS Ground Advantage: Ground parcel shipping service, offering an economical solution for medium to heavy parcels across the United States. Launched in 2023, USPS Ground Advantage has simplified ground parcel shipping by replacing several former services (such as Retail Ground and First-Class Package Service) with a single option for standard deliveries. This service is suitable for shipments that do not require maximum speed, while including basic tracking at no additional cost.
• Priority Mail: Priority mail and parcel service, widely used for fast shipments nationwide. Priority Mail offers expedited delivery within the country, without a specific time guarantee, but generally faster than standard mail. Priority Mail shipments automatically include detailed tracking and basic insurance. Additionally, USPS provides special free Priority Mail packaging (flat-rate boxes or envelopes) to facilitate fixed-rate parcel shipping regardless of weight, within certain size limits.
• Priority Mail Express: This is the fastest postal service offered by USPS for domestic deliveries. Formerly known as Express Mail, Priority Mail Express guarantees very fast delivery (often the next day or within 1 to 2 business days depending on the destination, although we do not specify an exact time frame here). This service includes a money-back guarantee in case of failure to meet the guaranteed delivery date, proof of delivery with optional signature, as well as detailed tracking of the shipment. It is the preferred service for urgent shipments that must reach their destination as quickly as possible.
• Media Mail: Economical postal service for sending media and educational materials such as books, printed documents, manuscripts, records, CDs/DVDs, and other recorded media. The Media Mail rate is lower than standard services, in exchange for a longer delivery time and strict content restrictions (only eligible media can be shipped via Media Mail). This service is popular with libraries, educational institutions, or second-hand book sellers to ship lots at a lower cost.
• International services: USPS also provides mail and parcel delivery to over 190 countries worldwide. Several options exist depending on the urgency and nature of the shipment:
  • First-Class Mail International: for sending letters, documents, and small lightweight packages abroad, economically. This service is ideal for shipments that do not require expedited delivery. Small First-Class International packages (often limited to 4 pounds, or ~1.8 kg) sometimes include partial tracking to the destination, depending on the country.
  • Priority Mail International: for larger or faster international parcels and correspondence. Priority Mail International shipments benefit from full tracking and basic insurance. This service serves most countries with competitive delivery times for a moderate rate.
  • Priority Mail Express International: the international express version of USPS, offering priority shipping to many countries. It is the fastest international service offered by USPS, including a money-back guarantee for certain destinations in case of exceeding an agreed time frame. End-to-end tracking is available, and extended insurance is included. This service is recommended for documents or goods that must reach abroad quickly.
  • Global Express Guaranteed: premium international shipping service with guaranteed delivery times, offered by USPS in a logistics partnership (this service relies on an international express carrier to transport the package). Global Express Guaranteed (abbreviated GXG) ensures the delivery of documents and parcels to a large number of destinations in very short times (usually a few days). It includes detailed tracking and a money-back guarantee in case of delay. This service is the most expensive but also the fastest and safest for critical international shipments.
• Additional services and options: In addition to standard postage, USPS offers many value-added services to meet specific needs:
  • Registered Mail: offers maximum security for valuable items or important documents. Registered mail is securely sealed and manually tracked at each stage, with delivery against signature. This service includes extended insurance (up to high amounts) to cover the declared value of the item.
  • Certified Mail: allows obtaining proof of mailing and delivery for important letters. The sender receives a receipt when the certified mail is delivered (or a notification of delivery attempt). This service is often used for official mailings requiring traceability of delivery.
  • Insurance and declared value: option to insure a package up to its value, in addition to the basic insurance possibly included. In case of loss or damage, compensation may be paid up to the insured amount.
  • Return Receipt: provides a signed confirmation by the recipient, returned to the sender (in paper or electronic form) to prove successful delivery. This service is often combined with registered or certified mail.
  • Collect on Delivery (COD): service allowing the sender to request payment of an amount by the recipient upon delivery of the package (for example, the price of a sold product). USPS collects the payment upon delivery and then transmits it to the sender. This service ensures the sender is paid before handing over the sent item.
  • PO Box: rental of a secure mailbox in a USPS post office, where the customer's mail is kept. This allows an individual or business to receive mail at this box (convenient for having a stable address or keeping their physical address confidential). Different box sizes are offered for a subscription fee.
  • Online services and digital tools: USPS also offers a website and mobile app allowing the purchase of online postage (Click-N-Ship service), scheduling home package pickups, locating post offices, and tracking shipments in real-time. A service called Informed Delivery also allows residents to preview (via email) images of incoming mail addressed to them, offering increased transparency on upcoming deliveries.

Logistics infrastructure and routing process

To fulfill its mission over a vast territory, USPS relies on a colossal logistics infrastructure and well-established processes. The journey of a shipment within the USPS network involves several key steps:

Collection and drop-off: Mail and packages enter the USPS network either by direct customer drop-off (in street mailboxes, at post office counters, in blue collection boxes, or via scheduled home pickups), or by outgoing mail collection performed by mail carriers during their route. Locally collected shipments are first transported to the nearest post office or local center.

Initial sorting and shipment to regional center: At the originating post office or a small local center, an initial sorting takes place to group shipments by major destinations (by destination zip code, for example). The mail bags and containers thus formed are then transferred to an appropriate regional processing center. USPS operates numerous sorting and distribution centers across the country, often called Processing & Distribution Centers or Network Distribution Centers for large-scale sorting. It is in these regional facilities that shipments will be finely sorted to prepare for their transport to the destination region.

Mechanized sorting and automation: In sorting centers, USPS uses modern and largely automated logistics equipment. High-speed sorting machines equipped with optical character readers (OCR) and barcode scanners process letters and packages. Addresses are read automatically, and items are directed to the correct exit area based on zip code or route. Standard letters, for example, are sorted by automatic sequencers that can process tens of thousands of items per hour. For packages, automated conveyors and belt sorters direct parcels to the correct shipment. This automation ensures efficient processing despite the enormous volumes handled daily.

Transport to the destination: Once sorted by region or route, batches of mail and packages leave the originating processing center to be transported to the destination area. USPS mobilizes different modes of transport for this: Road transport: The postal network has its own fleet of trucks and vans to transport mail between facilities, especially for short to medium distances. Chartered semi-trailers depart each night from major sorting centers to deliver sorted mail to other sorting centers or directly to local post offices. Air transport: For long distances or express shipments, USPS uses air transport. The agency does not own aircraft but has contracts with cargo airlines and commercial air carriers to quickly transport mail and packages across the country. For example, inter-coastal mail or mail to/from Hawaii, Alaska, and remote territories often travels by air. This partnership with air carriers helps maintain competitive delivery times across the territory. Rail transport and others: Historically, trains played a role in mail transport in the United States, and although their use has decreased, USPS still employs them in a limited way to move large volumes of mail on certain land routes. Similarly, special means (boats, small local planes, or all-terrain vehicles) may be used to reach isolated localities (such as villages in mountainous or island areas) not easily accessible by main roads.

Processing in the destination region: As the final destination approaches, shipments arrive at the regional distribution center serving the recipient's area. There, a new sorting is performed to distribute the mail by local delivery sector or by distribution post office. For example, a package destined for a given address will be directed to the local post office (sometimes called a delivery unit) that covers the recipient's neighborhood. This destination center scans the arrival of the package and prepares it for the final phase.

Final distribution and delivery: The last step takes place at the local post office or local distribution center. Mail carrier routes are organized each morning: the day's mail and packages are grouped and loaded into delivery vehicles dedicated to each route. USPS mail carriers, recognizable by their uniform and postal vehicle (the famous white vans stamped with the blue logo and eagle), deliver to the recipient's home or mailbox. Delivery is door-to-door in urban and residential areas (the carrier goes up to the recipient's mailbox or door), while in rural areas, grouped mailboxes or roadside mailboxes are used. Once the package or mail is delivered, a final barcode scan may be performed to confirm effective delivery.

The infrastructure required for these operations includes over 200 sorting sites and logistics centers across the country, as well as a vast fleet of vehicles. USPS operates the largest civilian vehicle fleet in the world, with over 230,000 vehicles in service (delivery vans, heavy trucks for intercity transport, etc.). Most urban delivery vehicles are vans specifically designed for postal service, with right-hand drive to facilitate distribution in roadside mailboxes. In rural areas, some carriers use their own personal vehicle, equipped with a magnetic postal badge during the route. The entire infrastructure is designed to smoothly handle considerable volumes of mail (over a hundred billion items per year). The logistics centers operate 24/7, and tracking and automation technologies help optimize mail flow in real-time.

In terms of security and reliability, USPS has dedicated internal services such as the United States Postal Inspection Service, which ensures the safety of shipments and combats mail-related crimes (thefts, postal fraud, etc.). Thus, while managing mass logistics, USPS emphasizes the confidentiality and integrity of the mail transported.

Postal shipment tracking system

Shipment tracking (USPS Tracking) is an integrated service in most USPS parcel and priority mail offers. A unique tracking number is assigned to each eligible shipment, allowing its status and journey to be tracked at any time. This tracking number, sometimes called a tracking number or article number on postal receipts, consists of a series of characters that uniquely identify the shipment in the system.

Tracking number formats: USPS tracking numbers can take several formats depending on the type of shipment: Domestic shipments (within the USA): generally a long numeric sequence, typically 20 to 22 digits. For example, a package sent via Priority Mail or USPS Ground may have a tracking number such as 9400 1234 5678 9999 9999 00. Some express or specific services may generate numbers starting with particular codes (e.g., 9270... for some Express, etc.), but they remain primarily numeric. International shipments: USPS uses the standard Universal Postal Union (UPU) format for international tracking numbers. This format includes two-letter prefixes, followed by nine digits, and then the country code of origin in two letters. For USPS, international shipments will typically have a number in the form XX123456789US (where XX is the type of shipment, for example, CP for a Priority Mail International package or EA for an International Express, ending with US for United States). This number is compatible with foreign postal tracking systems in the destination country. Special services: some services or specific labels may have slightly different formats. For example, military shipments abroad (APO/FPO) or certain merchandise returns may have numbers with specific prefixes, and registered mail shipments also have a tracking number often starting with RR or RF followed by the numeric sequence and US. However, in all cases, the principle remains a unique identification of the postal item.

Once the tracking number is assigned and the shipment accepted, USPS updates its tracking system at each key stage of postal transit. Each time the package or letter passes through a processing stage (for example) initial handling, departure or arrival at a sorting center, customs clearance, out for delivery, etc.), a scan of the barcode associated with the shipment is performed by postal staff. These scans update the shipment's status in the USPS database in real-time or near-real-time. The customer can then check these updates in several ways: by entering the tracking number on the official USPS website, via the USPS mobile app, by calling the automated customer service, or even using alert services (SMS or email) offered by USPS. Each tracking request returns the latest known status of the shipment as well as the history of previous statuses with their date, time, and location.

USPS shipment tracking is a free service included with virtually all domestic parcel shipments (Priority Mail, Ground Advantage, etc.) and with priority or express international shipments. For ordinary mail (First-Class letters without additional service), tracking is not provided by default due to the nature of this economical service, but it is possible to obtain traceability by opting for complementary services such as certified or registered mail. Similarly, some small economical international shipments only have partial tracking (for example, tracking until leaving the United States). Overall, the USPS tracking system offers senders and recipients transparent visibility on the routing, which enhances the perceived reliability of the postal service.

The tracking statuses generated by USPS are standardized and precisely indicate the stage of the process at which the shipment is located. Below, a table summarizes the main USPS tracking statuses and their meaning in English:

Interpretation of postal tracking statuses