What is a shipping label?
A shipping label is a printed document you attach to a package so that carriers — USPS, UPS, FedEx, DHL — know where to deliver it, how to handle it, and who to charge if something goes wrong. It contains the sender address, recipient address, a barcode (tracking number), service type, and sometimes additional information like weight or declared value.
What information is on a label?
Every carrier label includes: (1) To/From addresses — the full postal addresses of sender and recipient, (2) Tracking barcode — a scannable barcode that lets both carrier and sender track the package, (3) Service indicator — what service was purchased (e.g., USPS Priority Mail, UPS Ground), (4) Routing codes — internal carrier codes that sort the package through the network, and (5) postage amount or permit information.
How labels are generated
Shipping labels are generated by purchasing them directly from carriers or through a licensed postage reseller. CryptoPostage is a postage reseller — we buy your label from the carrier API (USPS, UPS, FedEx, or DHL) after you pay, and provide the resulting PDF for you to download and print. The label is a real, carrier-purchased postage document — not a printout you pay for at the post office.
What happens after you drop off the package
The carrier scans the barcode at each processing facility. You can track this through the carrier's tracking page (usps.com, ups.com, etc.) using the tracking number on your label. Most USPS labels are scanned at acceptance, at major sorting facilities, and at delivery. UPS, FedEx, and DHL have similar tracking infrastructures.
Printing requirements
Labels must be legible and firmly attached. Most home and office printers work fine on plain paper — print at 100% scale, do not shrink to fit. Cut the label and tape it securely to the largest flat face of the package, with no tape over the barcode. Thermal printers (like the Rollo or Dymo 4XL) print directly on thermal label stock — no ink, no tape needed.