When shipping USPS® packages, you generally shouldn't have any trouble as long as you're handing the package to the Postal Service within a few days of the date on the label... but it is at the discretion of the USPS employee, so be super nice about it 😉
UPS® prefers that you use your labels as soon as possible after purchasing them. If UPS considers a label too old to use, there's a chance that the package will be routed to a UPS Overgoods location, which is a facility where UPS holds packages that are unable to be recovered 🙈
If a UPS label has been sitting without being used, the best practice is to simply recreate it and pay for a new one! Keep in mind that our software automatically refunds labels after 28 days. If your UPS label is auto-refunded, you'll need to recreate that label and not use the original refunded label when shipping out your package 👍
If you use a refunded label or if you use a label more than once, that package will get sent to a UPS Overgoods location and will be unable to be recovered.
Unfortunately, once you’ve purchased a label there is no way to edit it. So, if you need to change the Ship Date, you will have to request a refund for the label and start over.