Tape the edges, leave the bars bare. The Postal Service instruction is one sentence long: “Do not cover USPS barcodes with tape or plastic wrap that may negatively impact readability of these barcodes” (Parcel Labeling Guide version 3 release 5, postalpro.usps.com, read 2026-07-28).
That is the rule for a normal carton. There is exactly one situation where a carrier tells you to do the opposite, and knowing which situation you are in is the whole of this page.
Border tape holds the label down. Tape across the bars is where the scan starts failing.
Notice the exact wording above. It does not say tape is forbidden anywhere near a label. It says do not cover the barcode with anything that may hurt readability, which is a performance test rather than a ban, and the two ways ordinary packing tape fails that test are worth knowing.
USPS also states the consequence in its own words: “Improperly applied shipping labels can cause scanning problems and affect the quality of tracking data provided by USPS.” That is the polite version of a parcel going quiet for four days while somebody keys it in by hand.
UPS publishes packaging guidelines with a section on irregularly shaped items and bare metals, and for those it says the opposite of the rule above: “Tape the address label on a flat surface of the item being shipped. Cover the label with clear tape.” The same instruction appears for tires, where the label goes on a band of tape wrapped round the tread and then gets covered in turn (ups.com, checked 2026-07-28).
The logic is straightforward once you picture the parcel. An unboxed metal item has no surface an adhesive label will survive on, so protecting the paper beats protecting the scan, and those shipments are handled manually anyway. UPS adds an additional handling charge for exactly this category, which tells you where they end up.
For anything in a corrugated box, the same UPS document goes the other way and says to “Do not place the label on a seam, edge, closure or on top of sealing tape”, and to “Place a duplicate address label inside the box”. That inside slip is the cheapest recovery plan in shipping and almost nobody does it.
A heavy moving-sized box quoted through the SMKlog calculator on 2026-07-28, Newark, NJ 07102 to Atlanta, GA 30303. Any of these can be delayed by a strip of tape in the wrong place, which is a poor return on two seconds saved.
| Carrier | Service | Price | Window returned |
|---|---|---|---|
| FedEx | Ground Economy | $28.77 | 6-7 business days |
| UPS | Ground | $29.52 | 2-3 business days |
| FedEx | Ground | $41.48 | 5-6 business days |
| UPS | 3 Day Select | $43.48 | 5-6 business days |
| UPS | Ground Saver | $46.73 | none returned |
The economy tier came out dearest on this particular box, which is the opposite of the usual pattern and a good reminder that carrier habits do not survive contact with a specific carton. Seventy-five cents separated the two cheapest rows, while the widest gap in the table ran to nearly eighteen dollars.
Over the edges yes, over the barcode no. The USPS Parcel Labeling Guide instructs shippers to not cover USPS barcodes with tape or plastic wrap that may negatively impact readability of these barcodes, per postalpro.usps.com read 2026-07-28. Secure the label by taping around its border and leave the printed bars uncovered.
Because it is talking about a different kind of parcel. The UPS packaging guidelines cover irregularly shaped items and bare metals, and for those it says to tape the address label on a flat surface of the item and cover the label with clear tape, per ups.com checked 2026-07-28. On an ordinary carton, the same document says not to place the label on a seam, edge, closure or on top of sealing tape.
The parcel drops out of automated sorting and gets handled by a person, which is where days disappear. USPS puts it plainly: improperly applied shipping labels can cause scanning problems and affect the quality of tracking data provided by USPS. A parcel that stops updating in tracking has usually had exactly this happen.
You can, and the usual failure is wrinkling rather than tape. A label creased across the barcode misreads even when nothing is covering it, so smooth the surface before the label goes down, tape the border, and keep the code away from any part of the bag that will be pulled tight.