Formato do Número de Rastreamento da USPS: 20 e 22 Dígitos

USPS tracking numbers are typically 20 or 22 digits long and start with specific number patterns like 9400, 9205, or 9270. Unlike UPS (which starts with "1Z") or FedEx (which uses 12-15 digits), USPS numbers are longer and follow predictable prefix patterns based on mail class.

What is a USPS Tracking Number?

A USPS tracking number is a unique code assigned to trackable mail pieces. It shows where your package or letter is from acceptance to delivery. The format reveals what service was used: Priority Mail starts with 9205 or 9407, First Class Package starts with 9400, Certified Mail uses a different pattern entirely.

Common USPS Tracking Number Formats

USPS uses different tracking formats for different mail classes. The first four digits tell you what service was used.

20-Digit Format (Most Services)

Most USPS tracking numbers are exactly 20 digits. This includes Priority Mail, First Class Package Service, Parcel Select, and others.

Examples:

• 9400 1000 0000 0000 0000 00 (First Class Package)
• 9205 5000 0000 0000 0000 00 (Priority Mail)
• 9270 1000 0000 0000 0000 00 (Parcel Select)

The spaces aren't part of the actual number—they're just formatting for readability. When you enter a tracking number on usps.com, don't include spaces.

22-Digit Format (Certified Mail, Registered Mail)

Certified Mail and Registered Mail use 22-digit tracking numbers. These start with letter-number combinations rather than pure numbers.

Examples:

• EA 123 456 789 US (Express Mail International)
• CP 123 456 789 US (Certified Mail)
• RA 123 456 789 US (Registered Mail)

The two-letter prefix indicates the service type. The "US" at the end confirms it's USPS. International items often use these letter-prefix formats because they need to work with foreign postal systems that have different tracking standards.

13-Character Format (Global Express Guaranteed)

Global Express Guaranteed, which USPS operates with FedEx, uses a 13-character alphanumeric code.

Example: 82 000 000 00

This service is rare. USPS accepts the package but FedEx actually transports it internationally. You can track these on both usps.com and fedex.com.

Intelligent Mail Package Barcode (IMpb)

Some USPS services use a 31-digit barcode internally, but you'll only see a shorter tracking number as a customer. The longer code includes routing information encoded in the barcode itself, but the public tracking number is the standard 20 or 22 digits.

USPS Tracking Number Prefixes

The first 2-4 digits tell you what USPS service was used:

Priority Mail has two possible prefixes (9205 or 9407) because USPS changed their numbering system partway through. Both are still in use. If your tracking number starts with either, it's Priority Mail.

First Class Package also uses 9400, which overlaps with Priority Mail Express in some cases. The USPS system knows the difference internally based on the full number, but as a customer you can't tell from the prefix alone.

Understanding Common Prefixes

9400 - First Class Package / Priority Mail Express

First Class Package is the cheapest tracked option USPS offers. Delivery takes 2-5 business days depending on distance. This is what most eBay sellers use for small items under 1 pound.

Priority Mail Express is overnight or 2-day service with guaranteed delivery times and money-back guarantee if late. It also uses 9400 prefix, so you can't tell from the number alone whether you're getting Express or First Class—you need to check the tracking details.

9205 / 9407 - Priority Mail

Priority Mail is 1-3 business day delivery with free boxes and $100 insurance included. This is the standard service for online retailers. Regional Rate boxes can be cheaper than regular Priority Mail if you're shipping heavy items short distances.

Priority Mail doesn't have a delivery time guarantee, but it's faster than First Class in practice. Cross-country typically takes 3 days.

9270 - Parcel Select

Parcel Select is ground shipping for commercial customers. It takes 2-8 business days and is the slowest tracked option. USPS delivers it to the destination post office, then carriers deliver it on their regular routes when convenient.

This is what Amazon uses for non-Prime shipments in areas where they don't have their own delivery network. It's cheap but slow and low priority.

CP - Certified Mail

Certified Mail provides proof of mailing and delivery for important documents. You get a receipt when you mail it, and the recipient signs upon delivery. This is what people use for legal documents, tax returns, or anything where you need proof someone received it.

Certified Mail travels with regular First Class Mail, so delivery time is the same (1-3 days). The tracking just adds the proof of delivery signature.

EA / EC - Express Mail International

Priority Mail Express International for packages going outside the US. Delivery times vary by country—Canada might be 3-5 days, Europe 4-7 days, Asia 5-10 days.

Customs creates gaps in tracking. Your package hits customs, sits there for days with no scans, then suddenly clears and delivers. This is normal for international mail.

USPS vs UPS vs FedEx Tracking Numbers

All three carriers use completely different tracking formats.

USPS tracking numbers:

• 20 or 22 digits
• Start with 9400, 9205, 9270, or letter codes like EC, CP, EA
• Example: 9400128206227943500115

UPS tracking numbers:

• Start with "1Z" (most common)
• 18 characters total
• Can also be 9, 10, or 12 digits for legacy services
• Example: 1Z662F416878787827

FedEx tracking numbers:

• Purely numeric (no letters)
• 12, 15, 20, or 22 digits
• No special prefix
• Example: 986578617213

If you have a 20-digit tracking number and don't know the carrier, check if it starts with 9400, 9205, or 9270—that's USPS. If it's purely numeric but doesn't start with those, it's probably FedEx SmartPost (which uses 20 digits). When in doubt, paste it into both usps.com and fedex.com to see which recognizes it.

You can't track a USPS package on ups.com or fedex.com. Each carrier only tracks their own shipments.

Related: For detailed breakdowns of other carriers' tracking systems, see our guides on UPS tracking number formats and FedEx tracking number formats.

How to Track a USPS Package

1. Go to tools.usps.com/go/TrackConfirmAction
2. Enter your tracking number (remove any spaces)
3. Click "Track"

Tracking information stays in the system for 120 days after delivery for most services. After that, the number no longer returns results.

Tracking Without a Number

Track by Email

If you signed up for USPS Informed Delivery, you get daily emails showing what mail and packages are coming to your address. This works even if senders didn't give you tracking numbers.

Informed Delivery is free. It takes a few days to verify your address, then you see scans of letter mail and tracking for packages automatically.

Ask the Sender

The sender gets a receipt with the tracking number when they mail the package. Most online retailers email tracking numbers, but individual senders might forget. Ask them to check their mailing receipt.

Check Your USPS Account

If you created a usps.com account, packages addressed to you show up under "Informed Delivery" even if you don't have the tracking number. This only works for your home address, not PO boxes or business addresses in most cases.

Common Tracking Mistakes

Adding spaces or dashes

USPS tracking numbers don't have spaces in the actual code. When you copy from an email formatted as "9400 1000 0000 0000 0000 00," remove the spaces before pasting. The system wants 20 or 22 continuous digits.

Confusing similar digits

The number 0 (zero) looks like the letter O in some fonts. USPS tracking numbers for most services are purely numeric, so if you see what looks like a letter in the middle of a 9400-series number, it's probably a zero you're misreading.

Letter-prefix formats (CP, EA, EC, RA, LK) do have actual letters, but only at the beginning and end, never in the middle.

Checking too soon

Retailers generate labels hours or days before dropping packages at the post office. The tracking number exists immediately but shows "USPS awaiting item" or "Pre-Shipment Info Sent" until USPS scans it at acceptance. Give it 24-48 hours.

Using the wrong carrier's website

If your tracking number doesn't work on usps.com, it might not be a USPS number. FedEx SmartPost uses 20-digit numbers that look similar to USPS numbers. Try fedex.com if usps.com returns "not found."

Some sellers use multiple carriers and send generic shipping confirmations without specifying which one. If the number doesn't work, try all three: usps.com, ups.com, and fedex.com.

Not accounting for package handoffs

USPS works with other carriers in both directions. FedEx SmartPost hands packages to USPS for final delivery. UPS Mail Innovations does the same. When this happens, tracking shows on both carriers' websites, but updates stop on the originating carrier once USPS takes possession.

Conversely, USPS Global Express Guaranteed hands packages to FedEx. Track these on both sites.

Expecting weekend delivery

USPS delivers packages on Saturdays at no extra charge for Priority Mail and Priority Mail Express. Sunday delivery happens in some areas for Priority Mail Express and Amazon packages, but not for regular mail.

If your package scanned Friday evening, Saturday delivery is possible but not guaranteed unless it's Express. First Class Package and Parcel Select don't move on Sundays.

International Tracking

International USPS shipments use letter-prefix tracking numbers: EA, EC, CP, LK, LJ.

Customs creates gaps. Your package arrives in the destination country, goes to customs, sits there for 1-7 days with no scans, then clears and delivers. This is normal. Tracking shows "Inbound Into Customs" or "Processed Through Facility" with a foreign city name.

Some countries have terrible scanning. Your package might arrive at the destination country postal facility and not scan again until "out for delivery." This happens in parts of Central America, South America, Southeast Asia, and Africa. The package is moving, just not being scanned.

After USPS hands international packages to foreign postal services, tracking quality varies. European posts (Royal Mail, Deutsche Post, La Poste) scan reliably. Asian posts are hit or miss. African and South American posts rarely scan after arrival.

Troubleshooting Tracking Issues

"Tracking Number Not Found"

Wait 24-48 hours after receiving the number. The sender created a label but might not have dropped the package yet. If it still doesn't work after 48 hours, contact the sender—they either gave you the wrong number or haven't actually shipped it.

USPS sometimes takes 12-24 hours to update tracking after initial acceptance, especially for packages dropped at collection boxes or small post offices.

No Updates for 3+ Days

For domestic packages, this usually means it's sitting at a distribution center. USPS moves mail in batches, and packages can sit on pallets for 48-72 hours between scans in slower facilities.

Call 1-800-ASK-USPS if it's been more than 5 business days with no movement.

For international, gaps of 5-7 days are common when packages hit customs.

Package Shows Delivered But You Don't Have It

Check the tracking details for delivery location. USPS notes "Front Door/Porch," "Mail Room," "Parcel Locker," "Front Desk," or specific locations.

Look in parcel lockers if you have them. USPS puts packages in the large parcel lockers at apartment complexes and puts the key in your regular mailbox. Check your mailbox for a parcel locker key.

Ask neighbors. Carriers sometimes deliver to the wrong unit number in apartment buildings.

Check if someone else in your household grabbed it.

If it's genuinely missing, file a claim at usps.com within 24 hours. After that, USPS considers it delivered and won't investigate.

Delivery Exception

This means something prevented normal delivery:

• Incorrect address
• No access to delivery location (locked gate, dog, etc.)
• Business closed
• No secure location to leave package
• Weather delay
• Damaged package

Click the exception details in tracking. It explains what happened. "No Authorized Recipient Available" means signature was required but nobody was home. "No Access to Delivery Location" often means a locked gate or aggressive dog.

Stuck "In Transit, Arriving Late"

This status means the package missed its expected delivery date. Common causes:

• Missorted at distribution center
• Transportation delays (truck breakdown, weather)
• Holiday backlogs (Christmas, Valentine's Day)
• Staffing shortages

The package is moving, just slower than expected. USPS doesn't provide updated estimates when this happens—it just says "arriving late" until it delivers.

If it's been more than 7 business days past the original expected delivery date, file a missing mail search at usps.com.

"Alert: Arrival at Unit"

This appears when the package reaches your local post office but hasn't been loaded on a delivery vehicle yet. It usually delivers the next business day.

If you see this status for more than 2 business days, your package might be sitting at the post office waiting for you to pick it up. This happens when:

• It's too large for your mailbox and carrier didn't attempt delivery
• Signature was required but nobody was home (they don't always leave a notice)
• There's a delivery restriction on your address

Call your local post office directly. The 1-800 number can't always see what's happening at individual post offices.

USPS Informed Delivery

Informed Delivery is a free service that emails you daily images of letter mail and tracking updates for packages coming to your address.

How it works:

• Sign up at informeddelivery.usps.com
• USPS verifies your address (takes 3-7 days)
• You get daily emails showing scans of letters and package tracking
• Works for your primary residence only (one address per account)

This is useful when sellers don't send you tracking numbers. You see packages coming even if nobody told you they shipped something.

The letter scans are from the sorting machines. They photograph the front of each letter addressed to you. You can't see the backs or what's inside, just the front envelope.

Package tracking in Informed Delivery sometimes shows packages before they're "officially" trackable. You might see a package listed with no tracking details yet, then full tracking appears 12-24 hours later.

USPS Tracking FAQs

Q: How long does USPS keep tracking information?
A: 120 days after delivery for most services. International mail might be longer. After that, the tracking number returns "not found."

Q: Can I track USPS with a FedEx number?
A: Only for FedEx SmartPost or UPS Mail Innovations. These services hand packages to USPS for final delivery, so the same tracking number works on both carriers' websites after the handoff.

Q: Why does my 20-digit number not work?
A: Make sure it's exactly 20 digits with no spaces or letters (except for formats like CP, EA that start with letters). If it still doesn't work, it might be a FedEx SmartPost number—try fedex.com.

Q: Can tracking numbers be fake?
A: Yes. Scammers send fake tracking numbers that look valid but don't exist in USPS's system. Always verify on usps.com, not just third-party tracking sites.

Q: What's the difference between Priority Mail and First Class Package?
A: Priority Mail is faster (1-3 business days), includes $100 insurance, and comes with free boxes. First Class Package is cheaper but slower (2-5 business days) with no insurance. Both use similar tracking number formats starting with 9400.

Q: Do all packages get tracking numbers?
A: No. Regular letters and USPS Marketing Mail (bulk mail/junk mail) don't have tracking. Only packages and trackable services like Certified Mail, Priority Mail, First Class Package, and Parcel Select get tracking numbers.

Q: Can I redirect a package after it's shipped?
A: Yes, with Package Intercept service. You pay a fee ($15-20) and USPS attempts to reroute the package. Success isn't guaranteed—if it's already out for delivery, they can't intercept it. Request intercept as soon as possible for best results.

Q: Why did my package go to the wrong state?
A: USPS routes through regional distribution centers. A package from Florida to Georgia might scan in Ohio because that's the hub. This seems inefficient but it's how the network is designed. The package isn't lost—it's following standard routing.

Q: What does "Departed USPS Regional Facility" mean?
A: The package left a regional distribution center and is on its way to either another facility or your local post office. Next scan should be "Arrived at USPS Regional Facility" or "Arrived at Post Office."

Q: Can USPS deliver without updating tracking?
A: Rarely. Carriers sometimes forget to scan packages at delivery, especially if they're rushing to finish a route. The system usually catches up when they return to the post office and scan the "delivered" status, but there can be a delay.

Q: Why does tracking say "Delivered" to mailbox but it's not there?
A: Check parcel lockers, look around your mailbox area, ask neighbors. Carriers sometimes mark packages delivered when they're still on the truck because they scanned them early. Give it a few hours.

If the carrier delivered to the wrong address, file a missing mail search immediately. USPS can often track down the carrier and find out where they actually left it.

Q: What does "USPS in possession of item" mean?
A: USPS has the package and scanned it into their system. This is the first real tracking event after label creation. Previous status was "Pre-Shipment" or "USPS Awaiting Item."

Additional Resources

• USPS Tracking
• USPS Mobile App
• USPS Informed Delivery
• Customer Service: 1-800-ASK-USPS (1-800-275-8777)
• USPS on X

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For further assistance, contact USPS directly or visit your local post office.