How do I Determine Check Digit for United Parcel Service Identification Number?

UPS uses check digits to verify the accuracy of package identification numbers.

United Parcel Service, or UPS, uses a unique identification number on each package. The 13 digit number contains 12 digits plus a check digit. The check digit is obtained by dividing the 12 digits by seven--the check digit is the remainder. The method is employed to catch transpositional errors, where numbers are accidentally typed or written down incorrectly. UPS isn't the only company to employ this type of check digit; Fed Ex, Avis and National all use the same check digit scheme.

Things You'll Need

• UPS label or receipt
• Scientific or graphing calculator

Instructions

1. Locate the 12 digit number on the UPS label or receipt.

2. Enter the 12 digit number into your calculator.

3. Press the "Modulo" button. The location of the modulo button on your calculator will vary by the brand. The modulo key may be labeled "Mod," or you may have to search the calculator's catalog--try pressing the "Cat" button--to locate the "Modulo" feature.

4. Press the "7" key on your calculator, then press the "Enter" key. The calculator will return the remainder for the calculation. This is the check digit.

Tips & Warnings

• If you don't have a scientific or technical calculator, try the math learning center of your local community college. They sometimes have technical calculators for loan.

References

• University of Georgia: Identification Numbers
• For All Practical Purposes: Mathematical Literacy in Today's World, COMAP, 2002