Weird that they even bothered to list the app for download in the Canadian app-store.
Anyways, with the Clipper card if you're going to use the app just add it to your phone's wallet and use your phone to tap the card readers. Alternatively you should still be able to top your card up at any place that sells Clipper cards – but that may take a day or two to update. As annoying as that is, both BART and Muni made paying for a subway ride with cash as excruciating as possible. You were boned if you wanted to pay with a $20 bill. Or if you wanted to use a credit card to pay for a BART ticket at the some of the ticket machines at some of the poorer stations.
Reach out to Streetsblog or SFist if you want to bubble up the complaint.
How in the world did you figure out that trick?
Unlike some Visa cards, MasterCard is apparently a global network with very little difference crossing borders. So this trick works outside the US too. Generally the address is checked by humans at some step, and an address “close enough” (at least the street address and name needs to match), then the transaction is often allowed through. If it doesn’t go through, tell your credit card company you often make purchases online from country X and your card will usually be flagged to allow it in future.
Online shops will usually accept 00000, but if it asks for your zip at a physical terminal you’re screwed.
A hint ; the padding doesn't have to be zeros (for my bank, when it approves during checks). So for example if you are doing 12300, this may not be a valid zip code.
In my case, my 12300 wasn't valid. I clued into this, because the code worked in most places where it should, but not a few others. I then looked up some codes, and realised that 12300 wasn't a real zip code.
So I Googled, and tried 123xx, where xx matches a real, valid zip code.
This gets by some checks, which table-lookup against valid zip codes, before sending a request to validate the zip remotely.
Even better, I then found an address for a condemned building on that same zip code. When required, I used that address as the 'bill to' address, and even that works sometimes. Very helpful when snowbirding, and spending 4+ months in the US.