You can use zone tables to measure the distance from the shipping location to the destination. If the client ships from multiple locations, you will need to define a zone table for each location.
Maintain zones window

From Subscriptions, select Set up tables > Maintain zones
Zone Tables
List of available Zone tables
Ship Method
Specifies a form of transport or any carrier that you use to ship your orders. You can use the lookup icon to select a shipping method when you have created the SHIP_METHOD general lookup/validation table and defined shipping zones.
Country
Specifies a country for the zone, or use the lookup icon to select a country. You define countries on the Set up country names window (from Customers, select Set up tables > Country names).
Title
Specifies a descriptive title of the zone table.
Table
Specifies the ZIP code and zone information the zone table contains.
To define a zone table
1. From Subscriptions, select Set up tables > Maintain zones to open the Maintain zones window.
2. Click New.
3. Enter the Ship Method of the zone table you are defining, or click the Find icon to select a value.
4. Enter the Country for the zone, or click the Find icon to select a country.
5. Enter the Title of the zone table.
6. Enter the shipping zone information for the zone table in the Table field. The table format for defining zones is XXX,Z or XXX-XXX,Z, where XXX is the first three characters of a postal code, and Z is a user-defined zone.
7. Click Save.