It’s documented at some gas stations near the border, also common on some forums. If padding with 00 doesn’t work, try 01, 02, etc. If filling in an online order form, it’s best to write in as much of your real address as possible, but zip code validation often means the city and state has to match the fake zip code. (This can have sales tax implications.) To avoid this, you can sometimes add US addresses to your credit cards as an alternate address, though I pretty much never do this.
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.
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.