Issue late instead of early
The whole benefit of pay-on-use is avoiding spend on labels nobody uses. Waiting for the buyer to say the box is packed gets you most of that benefit with no account and no negotiation. It costs one extra message.
Pay on use
Scan-based return labels: how a label that only bills when used works
A scan-based return label is created and sent in advance but only charged once a carrier physically scans the parcel into its network. FedEx states the arrangement outright on its own shipping pages, read 2026-07-27: the account is only charged when the label is scanned, and an unused one can be cancelled from Ship History before that happens.
Carrier rules quotedOur own position stated plainlyVoid windows for three carriers
The scan is the billing event
Carriers that bill on first scan turn a return label into a promise rather than a purchase.
Holding a prepaid label a store already sent you? Use it and stop here. It is already scan-billed to their account and nothing below changes that. This page is for people deciding how to issue return labels of their own.
What the carriers say about the billing moment
Three sets of rules, each read on the carrier's own support pages. They do not agree on much except that an unused label should not stay billable forever.
| Carrier | What triggers the charge | Getting out of an unused label |
|---|---|---|
| FedEx | The account is charged when the label is scanned, not when it is created | Cancel any time before the scan through Ship History |
| UPS | Not published as scan-triggered on the support page we read | Void online within 90 days of creating the label; between 90 and 180 days you contact UPS to request it; after 180 days a void will not be processed |
| USPS | Not published as scan-triggered on the refunds page we read | Unused Click-N-Ship labels are eligible for refunds up to 60 days after the print date, with the online request path covering labels created in the past 30 days; the label must not have been scanned by the postage system |
Printed labels usually have two weeks of validity, while emailed labels stay printable for up to two years.Per fedex.com shipping pages, retrieved 2026-07-27
The practical read: FedEx describes the closest thing to true pay-on-use, and the other two run refund and void windows instead. A void window is not the same as never being charged, because the money leaves first and comes back later, if it comes back.
Who can actually issue one
- Account holders with the carrier. The pay-on-use arrangements above are described in the context of a carrier account being charged. That is the shape of the product: the carrier extends credit against an account it can bill later.
- Retailers running a returns portal. The label your buyer generates from a store's returns page is usually one of these, which is why a store can hand out thousands of labels a day without paying for the ones nobody uses.
- Not a guest checkout. A one-off purchase has no account behind it to bill later, so the money has to move at the point of sale. That includes ours.
Our own position, stated plainly: SMKlog charges for a label when you buy it, not on first scan. We do not offer pay-on-use return labels. If the label goes unused, our terms say it may be eligible for a carrier void or postage refund only when the selected carrier allows it, and those refunds are not certain and can take time to process. Pricing is on the pricing page.
What a paid-up-front return label costs instead
The counter-argument to pay-on-use is that for a small seller the exposure is small in the first place. A 0.7 lb poly-mailer return, quoted through the SMKlog calculator on 2026-07-28, at the full checkout price.
| Carrier | Service | Price | Window returned |
|---|---|---|---|
| USPS | Ground Advantage | $8.86 | 5-6 business days |
| FedEx | Ground Economy | $10.06 | 5-6 business days |
| UPS | Ground | $10.31 | 2-3 business days |
| USPS | Priority Mail | $14.49 | 5-6 business days |
| UPS | 2nd Day Air | $15.38 | 2-3 business days |
At $8.86 a label, a seller who issues ten return labels a month and sees seven of them used is carrying $26.58 of unused postage before any refunds land. That is a real number but a small one, and it shrinks to nothing if you wait until the buyer confirms they are shipping before you buy anything.
Emailed labels last longer than printed ones
FedEx publishes a two-year printable life for an emailed label against roughly two weeks for a printed one. If a return is going to be slow, sending the PDF and letting the customer print it later is the version with more room in it.
Void windows are worth diarising
UPS stops processing voids after 180 days and USPS refund eligibility on unused labels runs to 60 days from the print date. A label bought and forgotten in a quiet month can quietly pass both marks. A calendar reminder is cheaper than the postage.
Pay-on-use label questions
What is a scan-based return label?
A label created and handed out in advance that only bills when the carrier scans the parcel into its network. FedEx describes this on its own shipping pages, read 2026-07-27: the account is charged when the label is scanned, and an unused label can be cancelled through Ship History before any scan happens.
Does SMKlog offer pay-on-use return labels?
No. We charge when you buy the label, because a guest checkout has no account behind it for a carrier to bill later. If the label is never used, our terms say it may be eligible for a carrier void or postage refund only where the selected carrier allows it, and those refunds are not certain and can take time.
How long do I have to void an unused label?
It depends on the carrier. UPS publishes a 90-day online void window, a request path between 90 and 180 days, and no voids at all after 180 days. USPS publishes refunds on unused Click-N-Ship labels up to 60 days after the print date, with the online path covering labels created in the past 30 days and the label not having been scanned.
How much unused postage does a small seller risk?
Less than the effort of chasing a pay-on-use arrangement, usually. A 12 x 9 x 1 in poly mailer at 0.7 lb going from Atlanta, GA to Newark, NJ quoted $8.86 with USPS Ground Advantage on 2026-07-28. Ten labels a month with three unused is under thirty dollars of exposure before any refund lands.