I just wanted to notify the many folks eager to sign up to the Yahoo! Publisher Network that if you do not enter in a company name, you will get paid (currently) to your username. The name you use to login to your YPN account. This information comes by way of a posting at our new forums, in which YahooSarah, an official Yahoo! company representative, came in to provide the following answer;
I'd like to clarify how Yahoo! determines the payee name to include on Yahoo! Publisher Network payments. When you sign up to be a publisher in the Yahoo! Publisher Network, one of the first things you do is fill out an Account Information tab with your name (first and last), company name and web site URL. We make our payment checks out to the name listed under "Company Name." If you do not represent a company or cannot cash a check with that company name on it, please enter your first and last name in that field.
I apologize for the confusion - we will be updating the language on this site tab soon to make this more clear. Rest assured, we do not use your user name on your check.
We value our publisher feedback and really do listen to your suggestions, so please continue to post your thoughts here.
Forum discussion at Search Engine Roundtable Forums.
Update: Yahoo emailed me to clarify that they normally do not use the username in the pay to field. Normally they will follow up with the publisher if it is unclear. They want to clarify, put something in the Company Name field, even if it must be your First and Last Name.