A USPS tracking number is not a random string — it is a labelled diagram of your shipment. Learn to read it, and a glance tells you the service class, whether it is certified or registered mail, and whether the number in your hand is even genuine. This guide dissects the formats block by block, starting with the one you will see most: the 22-digit number.
Anatomy of the 22-Digit Number: 9400 1102 0088 1260 3812 34
Most USPS parcels — Ground Advantage, Priority Mail, Certified Mail — carry a 22-digit number. Read it in four blocks:
- Digits 1–2 (94): the application identifier — 94 marks a USPS tracking label. Nearly every genuine 22-digit USPS number opens with 92, 93, 94 or 95.
- Digits 3–4 (00): the service type code. 00/01 typically mark Priority Mail and Ground Advantage; 07 marks Certified Mail (so 9407… is the classic certified-mail prefix); 16, 23 and others map to further services.
- Digits 5–20: the serial number — unique to your item, assigned by the mailer or the post office.
- Digits 21–22: check digits, computed from the rest so the system catches typing errors.
So 9400 1102 0088 1260 3812 34 reads as: genuine USPS label, Priority/Ground service, one unique item. A “USPS” number that is 18 digits long, or opens with 61, is not this format — check which service actually sent it before assuming the tracker is broken.
The 13-Character Express Format: EA123456789US
Priority Mail Express — USPS’s fastest domestic service — uses the international UPU shape instead: 2 letters, 9 digits, 2 letters. A genuine Express number looks like EA123456789US. The EA prefix (sometimes EC) marks Express; the closing US is the country code. Because it follows the UPU S10 standard, this is also the format most likely to keep working if your Express item transfers to a foreign post — the same structure India Post uses (see our India Post number decoder).
Registered, Certified and the Odd Ones
- Registered Mail: 13 characters opening with RA (e.g. RA123456789US) — the most secure USPS service, with a full chain of custody. If someone claims “registered” but the number is 22 digits starting 9400, it is not registered mail.
- Certified Mail: 22 digits starting 9407 — proof of mailing and delivery, the standard for legal and tax documents.
- Global Express Guaranteed: just 10 digits starting 82 (e.g. 8234567890) — the DHL-partnered international express product. Its short length surprises people; it is genuine.
- APO/FPO/DPO military mail: uses the standard 22-digit or Express formats above — the number looks ordinary even when the destination is a warship.
Informed Delivery: See Mail Before It Arrives
A free USPS service worth knowing: Informed Delivery emails you grayscale preview images of incoming letter mail each morning, plus package tracking summaries. It does not replace the tracking number — parcels still need their 22-digit code for real-time scans — but it answers “is anything coming today?” without a tracker. Sign-up is free on usps.com with address verification. Note it covers the US delivery address, so it helps the sender’s side confirm dispatch, not an Indian recipient waiting on an inbound parcel.
Where to Find Your Number (and the Fakes to Ignore)
The real number lives on the post office receipt, the shipping label, the online postage confirmation email (Click-N-Ship, eBay, Amazon), or the sender’s dispatch message. What is not a tracking number: the order ID from the store, a PayPal transaction ID, or a “confirmation number” from a marketplace. Scam texts claiming “USPS: your package 9400…” with a link are rampant — USPS never sends tracking links by unsolicited SMS. Type the number into usps.com yourself instead of tapping any link.
Track It: What the Statuses Actually Mean
Enter the number on the official tracker (or follow our USPS tracking walkthrough). Three statuses confuse everyone: “Pre-Shipment” means the label was created but USPS has not received the item — the seller printed postage, nothing more. “In Transit to Next Facility” can sit unchanged for days; it is a catch-all, not a location. “Delivered” with no parcel usually means it went to a neighbour, a parcel locker, or the wrong box — wait 24 hours and check with household members before filing a claim. Shipping to the USA from India? See our India–USA courier cost guide.
Frequently Asked Questions
How many digits is a USPS tracking number?
Most are 22 digits (e.g. 9400 1000 0000 0000 0000 00). Priority Mail Express uses 13 characters (EA123456789US), and Global Express Guaranteed uses 10 digits starting with 82.
What does a USPS tracking number starting with 9407 mean?
The 07 service code marks Certified Mail — USPS’s proof-of-mailing service for legal documents. 9400/9401 typically indicate Priority Mail or Ground Advantage.
Why does my USPS tracking say “Pre-Shipment” for days?
The sender created the label but has not handed the item to USPS yet. Until the first “Accepted” scan appears, the parcel is still with the seller — contact them, not USPS.
Can I track a USPS package in India?
Yes for the US leg on usps.com. Once a USPS international parcel enters India, the same number often continues to show scans on India Post’s tracker — try it there if USPS tracking goes quiet after “Departed” the USA.
Is a 10-digit USPS tracking number real?
Yes — if it starts with 82. That is the Global Express Guaranteed format (USPS’s DHL-partnered international express). Any other 10-digit “USPS” number is suspect.
Last verified: 19 October 2026. USPS formats per USPS published labelling standards; example numbers are format illustrations, not real shipments. Track only on usps.com — never via links in unsolicited messages.