USPS Rate Calculator API Upgrade

30 November 2011
USPS LogoThe United States Postal Service offer an array of shipping options connected to an online rate calculator that NitroSell uses to calculate shipping prices for shoppers. From time to time USPS upgrades their rate API, and the old one is discontinued. USPS plan to discontinue their existing API by March 2012. In order to continue to offer USPS as a shipping method we have upgraded NitroSell eCommerce to handle the new API. This was done in such a way that doesn’t break existing users implementations.

Due to the essential nature of this upgrade and the extensive testing that it has undergone, we are releasing this upgrade to both the Beta and v5 stores. For those that want to revise their USPS implementation choices, or those interested in using the USPS for shipping then read on…

When a webstore gets a price for a customer from the USPS API, it makes some assumptions based on choices that you enter into your WebStore Manager. The webstore assumes that you will send a sale in a single ‘typical’ package with dimensions that you define in the Webstore Manager. It then looks at a list of parameters listed below and asks the USPS API for a price. This price is run through a rule system that allows the webstore manager to modify the USPS price according to the needs of the webstore.

Parameters that affect price:

  • Service: First Class, Priority or Parcel Post;
  • Size: regular (no dimensions over 12″) or large;
  • Container: rectangular, non-rectangular, or standard package issued by the USPS;
  • Machinable: can the package be sorted by machine;
  • Dimensions: length, width, height and sometimes girth.

Each service has requirements of it’s own, this means that though you can send a large 70 lb parcel using Parcel Post, the First Class Service won’t be interested in accomodating you. Below are links to the relevent parts of the USPS website where you can find size and weight limitations.

Shipping is dealt with on two different parts of the webstore.

Under ‘Configuration/ Webstore’ is a tab titled ‘Shipping’. In this tab you need to enter your typical package width, height, length and girth (for non-rectangular large packages) under USPS.

Under ‘Configuration/ Shipping and Taxes’ pick the country that you are posting to and add ‘Shipping Method…’ then under ‘Shipping Method’ select ‘USPS (US Domestic Rate Calculator)’ as a shipping carrier and pick the Shipping Service that suits you best.

At the moment the shipping integration only covers USPS Domestic, if you are interested in International please get in touch and let us know.

Lastly, please note that USPS no longer offers Express Mail pricing through its API. If you currently have express mail shipping integration switched on, purchasers will be asked to contact the store to arrange an alternative shipping method. All stores using USPS should check their shipping integration and ensure it is working as they intended.