There are a lot of licensing restrictions that will make it extremely hard, if not impossible, for you to buy this from a third-party vendor. You'll need to sign a PAF(<a href="https://postalpro.usps.com/NCOALink_PAF" rel="nofollow">https://postalpro.usps.com/NCOALink_PAF</a>) with the NCOA service provider and if I remember correctly the smallest "batch" of addresses that the licensee can run at a time is of 100. The service provider also cannot run addresses via NCOA without actually sending a piece of mail to the address being processed.<p>Source: I helped build a USPS CASS-certified address verification and NCOA API at my previous employer. Dealing with USPS licensing was a PITA.
Companies that have signed up as full/limited service licensees to this API may be able to sell you access indirectly through their own API offering. They may be able to offer cheaper pricing if they spread the cost of the USPS fee across multiple customers. Lists of licensees with contact details are visible on the USPS site:<p><a href="https://postalpro.usps.com/ncoalink/Full_Service_Provider_Licensees" rel="nofollow">https://postalpro.usps.com/ncoalink/Full_Service_Provider_Li...</a><p><a href="https://postalpro.usps.com/ncoalink/Limited_Service_Provider_Licensees" rel="nofollow">https://postalpro.usps.com/ncoalink/Limited_Service_Provider...</a>
incredibly enough none of the FAANGS provide this simple targeting data-point ( on businesses ), but ironically they do offer almost everything else on them.<p>So if this data doesn't exist (US market)... perhaps some clever dev-team should try to aggregate/scrape this and make an affordable paid API service for it ;-)