I’ve stumbled across a puzzling mystery. If you live in the southern part of the city of San Francisco, or in a large area further south into San Mateo County, UPS will not sell you international shipping labels. But change your Ship From zip code to a different city just a few miles away, and UPS will be happy to quote you for international shipping. I reached this conclusion after spending many hours pricing dummy international shipments with different Ship From and Ship To addresses, package sizes and weights, and content types. Only the Ship From address seems relevant. A UPS agent confirmed this behavior but couldn’t offer any explanation or solution.

I first discovered this problem on April 4, while using the third-party shipping service Pirate Ship to generate some UPS international shipping labels. For all my packages, Pirate Ship offered US Post Office shipping options, but nothing from UPS. After several hours working with Pirate Ship’s tech support, they concluded UPS was declining international shipping service to this region for some unknown reason. They told me to take up the issue with UPS.

Initially I didn’t believe Pirate Ship’s explanation, but then I discovered I could reproduce the same problem directly at the UPS.com page for international shipping quotes. You can try this too. Go to the UPS international shipment cost calculator page, as a guest (not logged in). Enter these package details:

Ship From: United States, Redwood City, zip code 94065. Or mostly anywhere else in the United States, except one of the redlined areas listed below.
Ship To: France, postal code 75008, Paris. Or try any another major city in Europe, Asia, wherever, it doesn’t matter.
Customs Value: 119
Package Details: My packaging, 11 x 9 x 2 inches, 0.8 pounds, 119 dollar value

You’ll see a list of available UPS shipping methods with specific price quotes. For example, UPS Worldwide Expedited service costs $154.44 to Paris. You’ll get the same behavior with Ship From addresses in most parts of California or elsewhere in the United States.

Now try the same experiment again, but for the Ship From location, choose one of the following cities and zip codes. These cities are a contiguous geographic region just south of San Francisco, centered around the San Francisco airport. The total population is about 1 million people.

94002 Belmont
94403 San Mateo
94402 San Mateo
94401 San Mateo
94404 Foster City
94010 Burlingame
94030 Millbrae
94128 San Francisco
94112 San Francisco
94132 San Francisco
94066 San Bruno
94080 South San Francisco
94019 Half Moon Bay
94044 Pacifica
94015 Daly City
94005 Brisbane

When you repeat the test using one of these Ship From addresses, UPS.com complains:

The shipment descriptions you have indicated may require special assistance. Please check the accuracy of your request or contact your local UPS office for assistance.

This is consistent with the apparent UPS international shipping redlining that I observed when using Pirate Ship. I spoke with the staff at the local UPS Store, but they’d never heard of this problem, and said their outgoing international shipments were working just fine. Through trial and error, I discovered that Shopify Shipping isn’t affected by this problem either, so it may have something to do with the class of UPS shipping account used to buy shipping labels. The problem definitely affects Pirate Ship, UPS.com’s own shipping quote system, and probably others too.

I then spent a long time on the phone with other UPS support agents who told me I was wrong, and that the Ship From zip code didn’t matter for determining international shipping service availability. On the third try, I was finally able to demonstrate the problem to a UPS agent, but she could only say “I don’t know why it’s doing that”. She couldn’t offer any explanation or solution. That was several days ago, and the problem is still happening today.