Maybe somebody faced with such issue or can explain how UPS Zones work.
As i understand UPS uses Zone to calculate delivery price and time. So if you are close to the warehouse it's Zone 1, if you far from warehouse your zone is f.e 5. etc Is that correct? Or maybe i am wrong with this info.
Are there any way to calculate zone based on ZIP Code. My task for now is to find closest warehouse without API call to UPS. Are there any zip code matrix or any rule how can i do it?
I've found this url https://www.ups.com/us/en/shipping/zones-and-rates/invalid-zip-code.page?zipcode As i understand i need to download matrix per each warehouse. But how can i use it to detect zone and closest way?
UPS Sales can provide a spreadsheet with your zone and rate information by postal code. Beware that service availability (ex: Ground Saturday delivery) is always changing so depending on your needs, an API solution may truly be the best option - you could cache API results and flush periodically so you're not maintaining static tables.