Procedures for OS2 and Residential Charges

I routinely find errors on my UPS bill for adjustments on OS2 and Residential charges . I have fought these charges in the past and have received credit in the thousands of $$$. What is the method used by auditors at UPS to make these determinations on OS2 and Residential charges and how can it be so prone to error?

UPS has a list of zip codes that are charged the $1.75 residential surcharge. You can phone the 800 number or UPS.com to get the shipping cost.

Measure your box: Multiply 2 x width, 2 x height plus the length. If the total is over 84" and less than 108" then it is OS1 (30#), if the total is over 108" and less than 130" then is is OS2 (70#) if it doesn't already weigh that. OS3 will start in January--max of 165"

Hope this helps