I'm based in Puerto Rico and have a question regarding Amazon's Buy Shipping options for US mainland sellers. Do they automatically have access to carriers like UPS and FedEx? Despite extensive searching, I haven't found a clear answer. So far, my shipping has been limited to USPS, as other services seem unavailable. While USPS suffices, I'm eager to explore all available options for potentially better shipping deals. I've attempted to integrate a UPS account to access more options on Amazon Buy Shipping, but without success. I understand this might exclude me from certain Buy Shipping Benefits, but I wanted to explore the possibility.

I suspect the issue arises from Puerto Rico's unique status. Sometimes viewed as a sovereign entity by some services, shipments to the US may be considered international, hence excluding us from certain Amazon Buy Shipping options like UPS and FedEx. Alternatively, Puerto Rico's status as part of the US but not fully domestic in some contexts might be causing this ambiguity. As a US territory, I can use USPS, but this nuanced status seems to limit my access to other shipping services.