Printed under the barcode
USPS describes the tracking number itself as the series of numbers under the barcode on the label. On a flat rate label that barcode sits with the postage indicia, not hidden anywhere.
USPS flat rate
Does flat rate shipping come with tracking?
Yes, on every flat rate box and envelope you pay for at the time of mailing. Flat rate is a pricing rule applied to Priority Mail, not a separate mail class, and Priority Mail’s own page states plainly that it “includes USPS Tracking® and up to 100 USD of insurance with most shipments.” That wording was read at usps.com on 2026-08-31. The one carve-out sits on a different product entirely, and it is below.
Carrier wording, quotedRead 2026-08-31One named exception
The price is flat, the service is not new
A flat rate box is a Priority Mail shipment with its price fixed to the box. Everything Priority Mail includes rides along with it.
Flat rate is a price, not a mail class
The question comes up because “flat rate” sounds like it could be its own stripped-down product, the way a discount airline strips out a checked bag. It is not. USPS sells Priority Mail Flat Rate boxes and envelopes as Priority Mail with one rule bolted on: the price is set by which box you use, not by the scale. Nothing about the service underneath changes.
Read on the Priority Mail product page at usps.com on 2026-08-31: Priority Mail “includes USPS Tracking® and up to 100 USD of insurance with most shipments (restrictions apply),” on a published 2-3 day delivery window. The same page describes flat rate as letting a shipper “pay the same price for mailpieces weighing up to 70 lbs going anywhere in the U.S.” using the standard boxes and envelopes. There is no second, cheaper version of Priority Mail Flat Rate sold without the tracking bundled in — the pricing model and the service class are two different questions, and only one of them decides whether the box is trackable.
The one flat rate product that skips it
One flat rate product genuinely ships without tracking, and it is worth knowing before buying a stack of them.
| Product | Tracking | What decides it |
|---|---|---|
| Priority Mail Flat Rate box or envelope, paid at mailing | Included | Sold and priced as ordinary Priority Mail |
| Priority Mail Express Flat Rate box or envelope | Included | Same rule, faster Priority Mail Express class |
| Prepaid Forever Flat Rate box or envelope | Not included | USPS names it as the stated exception on the same tracking line |
The Prepaid Forever version is the same cardboard box with Forever postage already stuck on, bought ahead at store.usps.com or the counter so a rate increase later does not touch the price you locked in. That convenience is the trade: no tracking number, and the 100 USD of coverage that rides along with an ordinary Priority Mail shipment does not carry over either. Our Prepaid Forever page covers the mechanism and the price gap in full; nothing here repeats it.
Where the number actually lives
A peel-off strip on preprinted labels
A label printed at home or through a shipping account carries a peel-off portion at the bottom made to be kept for your own records — the number without the rest of the label.
On the receipt at the counter
Hand a flat rate box across a Post Office counter and the clerk’s printed receipt carries the same number the label does. Keep it; a receipt outlives a taped-over label.
The digit count, the fields inside the number, and how it differs from a UPS or FedEx number are their own subject, covered fully on our tracking number format page rather than repeated here.
What does not come with tracking by default
The contrast that actually matters is not inside the flat rate line — it is against the two USPS products built without a tracking barcode at all.
| Product | Tracking |
|---|---|
| Priority Mail Flat Rate (paid at mailing) | Included, no fee |
| USPS Ground Advantage | Included, no fee |
| First-Class Mail letters, postcards, flats | Not eligible at any price |
| USPS Marketing Mail parcels | Available only as a paid add-on |
USPS states it directly: “First-Class Mail postcards, letters and flats are not eligible for USPS Tracking service.” No amount of postage changes that, because the product carries no scannable barcode to begin with — a letter can add Certified Mail for a paper trail, but that is a different service, not tracking. Media Mail is not on this list because it is not exempt; our Media Mail tracking page shows the same free inclusion under the same USPS rule, even though the product page selling it never mentions the word.
Where these statements come from
- USPS, Priority Mail — tracking and coverage included, the 2-3 day window, and the flat rate description. Read 2026-08-31.
- USPS, USPS Tracking — The Basics — no added cost for tracking on products that include it, the Marketing Mail exception, First-Class Mail ineligibility, and where the number is printed. Read 2026-08-31.
USPS revises its product pages without notice. Treat the figures above as what usps.com published on the date shown, and check the current page before relying on an exception.
Flat rate tracking questions
Does flat rate shipping include tracking?
Yes for the standard Priority Mail Flat Rate boxes and envelopes. USPS states on usps.com that Priority Mail “includes USPS Tracking® and up to 100 USD of insurance with most shipments,” and flat rate boxes and envelopes are priced and sold as Priority Mail. The number is part of the service class, not an add-on you buy separately.
Why does tracking come with the box rather than the flat price?
Because flat rate is a pricing rule, not a mail class of its own. It fixes the price of a Priority Mail shipment to the box size instead of the weight, and everything else about Priority Mail — the tracking, the coverage, the 2-3 day window — carries over unchanged. Ask for tracking on a flat rate box and you are really asking whether Priority Mail has it, and it does.
Does every flat rate box or envelope come with tracking, no exceptions?
One exception exists. USPS lists USPS Tracking as included with Priority Mail Flat Rate shipments, then excludes Prepaid Forever Flat Rate products from that line — the same box with postage already applied ships without a scan history or the usual coverage. Every flat rate box or envelope paid for at the time of mailing keeps the tracking.
Where is the tracking number printed on a flat rate label?
USPS describes it plainly as the series of numbers under the barcode. A preprinted flat rate label carries a peel-off strip at the bottom worth keeping for your own records, and a label bought at the counter puts the same number on the mailing receipt. The digit count and structure behind it are on our tracking number format page.
What USPS services do not include tracking by default?
First-Class Mail postcards, letters and flats are not eligible for USPS Tracking at all — no fee unlocks it, because the product carries no scannable tracking barcode. USPS Marketing Mail parcels are the other exception, where tracking is available only as a paid add-on rather than bundled into the postage.