If you are not on scan based billing, UPS charges you as soon as you create the label. If you are not using that label, then you should void that label directly in your UPS account.
UPS Void Shipment
Within 90 days of creating your shipping label on UPS.com, you can still void the shipment through shipping history. The account number associated with the package you want to void must be an account in the UPS profile.
This is your option to void a UPS unused label after running the end of day process in UPS Worldship. If more than 90 days have passed since you created the label, you must contact UPS directly to request a void. After 180 days, UPS will no longer honor any void requests.