Why Can a Shipping Label Be Invalid?

Every mailpiece needs a valid shipping label to be delivered, otherwise it may get returned to sender, confiscated by the carrier, or simply lost. But what exactly does “valid” mean in this context? How can a shipping label be invalid? Let’s figure this out together.

A shipping label is a sticker or a piece of paper that contains information about the package, sender, and recipient. It also serves as proof of postage. A standard shipping label usually includes the sender’s and recipient’s names and addresses, the shipping method (level of service), a package number, a barcode (or a QR code, depending on the carrier) for automated package processing, and other relevant information (for example, international shipping labels contain a description of the package contents because they double as a customs declaration).

When you have a package shipped from a Post Office / carrier’s location, an employee will print a shipping label for you; you’ll only need to provide the required information and pay postage (and extra fees if applicable). However, you can also purchase and print shipping labels online to save time and money.

Sometimes packages are deemed undeliverable and get returned to sender, confiscated, or even lost due to an invalid shipping label. A shipping label can be flagged as invalid for several reasons; here are the most common ones.

No barcode. Every valid shipping label, regardless of whether it has been created by a shipping company employee or generated online by sender, has a scannable barcode for automated package processing that enables the carrier to provide delivery updates through its tracking system. If you simply print out or handwrite a mailing label with the sender’s and recipient’s addresses but with no barcode generated by the carrier, the carrier will have no way to register your package in the system, and your label will be considered invalid.

Incorrect or incomplete information. Any inaccuracies in the recipient’s address, such as missing or erroneous ZIP/postal code, incomplete address, or wrong address, can result in the shipping label being considered invalid.

Non-compliance. Even if your label has a carrier-generated barcode and a correct address, it may be considered invalid if it does not comply with the carrier’s standards and regulations (for example, if it is too big or too small, bent over the edge of the box, etc.).

Unauthorized alteration. Once you’ve generated and printed a shipping label, it cannot be changed. If you need to fix an error, you should void the label and generate a new one; if you try to alter the label manually, it will be considered invalid.

Damaged label. If the shipping label is damaged or torn, the barcode may become unscannable, and the carrier will not be able to process the package. This also applies to shipping labels that are too pale or smudged, so if you print shipping labels yourself, you need to make sure they are clear, legible, protected from the elements, and securely affixed to the package.

Expired or voided label. Most shipping labels must be used within a set time period after purchase, and they will be considered invalid if used past their expiration date. If a shipping label has been voided and refunded, but the sender still tries to use it, it will be considered invalid too.

Duplicate label. Theoretically, you can print multiple copies of the same shipping label; it may come in handy if you want to put a backup label inside the package in case the label on the package gets torn or damaged. However, each shipping label can be used only for one package. If you attempt to use copies of the same shipping labels for multiple packages or reuse a shipping label that has already been scanned into the system, the copies will be flagged as invalid.

Counterfeit label. If you want to purchase a shipping label online and print it yourself, you can do it on the carrier’s website or use an authorized shipping label printing service such as PostageMaker. Shipping labels purchased via authorized services are compliant with carriers’ regulations and have carrier-generated barcodes. However, there are services that produce counterfeit shipping labels to scam people out of money; their labels are invalid.

What happens to packages with invalid shipping labels? The outcome depends on the reason why the shipping label was flagged is invalid. Packages with incorrect or incomplete information, or with damaged, altered or non-compliant labels are returned to sender if he or she can be identified. However, packages with expired, voided, duplicate, or counterfeit labels may be confiscated by the carrier.