Carriers use shipping zones to calculate shipping rates. Shipping zones measure the gap in between a package deal’s place of origin and its location. In the US, these can array from Zone 1 to Zone 8. uShip's API https://thekiwisocial.com/story3374274/how-much-you-need-to-expect-you-ll-pay-for-a-good-how-shipping-rates-are-calculated-at-checkout