I'm unsure why you don't see them. For us, it's on most order pages right below the customer's address. I've just always assumed when it's not there, the custom

I'm unsure why you don't see them. For us, it's on most order pages right below the customer's address. I've just always assumed when it's not there, the customer didn't provide one. Most seem to have a phone number, however. We have a Pro account as well, and we see the phone number both in Seller Central as well as over the API (we currently are using a MWS API version from 2011, if that makes any difference). Regarding putting your own number on the package - that is what we do with 100% of our shipments from our warehouse, and we've done it that way for more than a decade without issue. The phone numbers are supposed to be mainly used for when there's an issue with delivery, but in our experience the carrier never calls (although it would be nice if they did sometimes... but I digress). We even put our phone number on international shipments (where I'd expect the most hassle due to customs), and never had an issue. Of course, YMMV...