What size is a UPS label?
Use 4 × 6 inches for thermal printers unless your UPS workflow explicitly gives a different format. For sheet printers, print at 100% scale on Letter or A4 and keep the barcode quiet zone intact. Do not crop the barcode or fold it around a package edge.
Thermal vs sheet printing
Thermal printers are faster and reduce scaling mistakes because the roll size usually matches the label. Inkjet and laser printers work best when you download the carrier PDF, open it in a PDF viewer and disable shrink-to-fit options before printing.
Troubleshooting scan problems
If the label is cut off, too small, not centered or not scanning, first confirm the print scale and paper size match the generated label. Then inspect print density, paper quality, tape glare and whether any barcode quiet-zone whitespace was cut away.
Carrier acceptance checks
Before dropping off a UPS package, verify the tracking barcode is sharp, the service text is readable and the label is attached flat. If you changed printer, browser, PDF viewer or label stock, print a blank test sheet before printing production labels.