If your luggage exceeds the billable weight that was paid for, you will be charged a low, prorated, per pound rate for any overages. You can calculate your per pound rate for overages by dividing the total transit cost by the total weight that was paid for in advance.
For Example
50 lb bag
Transit cost: $27.99
Per pound rate: $27.99 / 50lb = $0.56/lb
You can find your unique per pound rate after booking on your shipping label and drop off reminder email.