I'd like to share some information about the billing address, SMCK1.
If the address is for your subscription payment, then the card must have a US-based billing address. US territories are excluded. You can check this article for more details: Subscription payment options for QuickBooks Online.
For accepting payments from customers with Non-US credit card using QuickBooks Merchant Services, the address may have a ZIP code (or Province code) that include characters that didn't meet the U.S. 5 digit standard. If this is the situation, your customer will need to reach out to the card issuing bank.
Here's an article that you can read for reference: Accept Non-US credit card from customers using QuickBooks Merchant Services.
Please feel free to reply on this thread if you have any follow-up questions. I'm here to help you out some more.
