https://www.usps.com/business/web-to...is/welcome.htm

However, we (TaxCloud) no longer require a valid USPS ID, because we no longer use USPS APIs for address validation (because they have become increasingly unreliable). You can use a fake USPS ID, such as "111CLOUD1111" (which matches the USPS ID Syntax, just in case field verification is underway somewhere). This parameter will be depricated in future versions of our API.

;)