Tracking Number Detector
Paste any tracking number — identify the carrier and validate the format in one step.
Spaces and dashes are ignored. We never store what you paste.
Paste a tracking number above to detect its carrier.
A tracking number isn’t random. Every carrier issues numbers in a documented shape so its own routing and validation systems work, and that shape leaks enough information to identify the carrier without any live lookup. This page explains exactly how the detector reads that signal, and what to do when the answer is ambiguous.
Three signals, read in order
The first or last few characters often name the carrier outright.
- 1Z…UPS
- TBA…Amazon Logistics
- 3S…PostNL
- …GBRoyal Mail
- …CNChina Post
A fixed character count rules out most candidates instantly.
- 10 digitsDHL Express
- 12 or 15 digitsFedEx
- 14 digitsDPD
- 16 digitsCanada Post / Evri
- 20–22 digitsUSPS
Many carriers append a computed digit. A typo flips it and the match fails.
- UPSmod-based on 18 chars
- FedExmod-7 / mod-11
- USPSGS1 weighted
- UPU S10weighted mod-11
Reading the S10 postal suffix
International parcels sent through national posts follow the Universal Postal Union’s S10 standard: two service letters, nine digits, then a two-letter ISO country code. That last pair is the most useful field on the whole number — it tells you which national post handled the shipment.
Service letters, nine digits, origin code. The boxed "GB" is the part to read.
Format reference
Every pattern the detector recognises, with an illustrative example showing the structure (not a real shipment).
When the detector gives up
Many regional and last-mile couriers use plain numeric strings with no prefix, no fixed length, and no check digit. Two unrelated carriers can issue the same shape, so the number is mathematically indistinguishable. When that happens the original shipping email is the authoritative source — it always names the carrier.
- Length matches a real carrier’s pattern
- Prefix / suffix is one a carrier issues
- Check digit (when published) computes correctly
- Character class is right (letters vs digits)
- Whether a real parcel was lodged
- Whether the carrier has scanned it yet
- Whether the address is deliverable
- Whether customs has released it
Symptom → likely cause → fix
If nothing matched, or the carrier site shows nothing for a number that did match, find the row below. The order is the order to check.
Matched, but still no movement
The most common follow-up — and almost always a timing issue. A label exists as a number from the moment it is printed in the seller’s warehouse, hours or days before the courier picks it up. Until that first carrier scan, the number is real but the carrier’s tracking page has nothing to show.
Give it 24–48 hours (longer over weekends and holidays). If a few days pass with no scan, contact the sender to confirm the parcel actually shipped and that you have the right number.
Frequently asked
- How does the detector know which carrier a number belongs to?
- It walks the number through three signal layers in order: prefix or suffix (e.g. "1Z", "TBA", trailing "GB"), exact character length, and where applicable the carrier’s published check-digit formula. A match has to satisfy all of them.
- Does a match mean my parcel is on its way?
- No — a match means the number is shaped like a real tracking number (right length, right prefix, correct check digit). The parcel still has to be physically scanned by the carrier before live tracking events appear.
- It matches a carrier, but the carrier page shows nothing. Why?
- Almost always a timing gap. A label exists as a number from the moment it is printed, but the first scan happens when the parcel is collected — often 24 to 48 hours later, longer over weekends and holidays.
- Nothing matches — what should I check first?
- Character count, then character class. An "O" pasted for "0", an "l" for "1", a missing digit at either end, or an order/invoice reference copied instead of the tracking number are the four causes that catch ~95% of failures.
- What does "1Z" at the start mean?
- A "1Z" prefix followed by 16 alphanumerics is a UPS ground or air shipment. UPS also issues short waybill numbers that start with a single letter and ten digits for some lanes.
- A number ends in two letters — what is that?
- That is the UPU S10 postal format: two service letters, nine digits, and a two-letter ISO country code identifying where the item was posted. "GB" is Royal Mail, "CN" is China Post, "US" is USPS international, and so on.
- Why does the result show two carriers?
- Some shapes are genuinely shared. Canada Post and Evri both use plain 16-digit numbers; the S10 postal format is used by dozens of national posts. Pick the one whose origin country matches your order.
- Can I trust the check-digit verification?
- For UPS, FedEx, USPS, Canada Post and the UPU S10 standard, yes — those carriers publish the formula and a typo will fail it. For carriers without a check digit, the match is structural only.
- Some numbers just say "unknown" — why?
- Regional and last-mile couriers often use plain numeric strings with no prefix, no fixed length, and no check digit. Mathematically you cannot distinguish them by shape; the only reliable source is the original shipping email.
- Is anything I paste sent anywhere?
- No. Detection is a pure client-side function. The number never leaves your browser.