ZIP codes are an American thing. ZIP codes are a specific system of postal codes. If you are talking about ZIP codes, it's American.
If you are validating an American address, you'd want to validate using something that validates a ZIP code. If you get a Canadian address, you'd want to validate against that (which also happens to make it simple to validate against the province as well).
And yes, if you shouldn't using the term ZIP codes and postal codes interchangeably and treating them the same way in your code.
If you are validating an American address, you'd want to validate using something that validates a ZIP code. If you get a Canadian address, you'd want to validate against that (which also happens to make it simple to validate against the province as well).
And yes, if you shouldn't using the term ZIP codes and postal codes interchangeably and treating them the same way in your code.