Does a dealer have to send his license with a firearm being transferred, or does the recipient have sole responsibility to send one?
Um, no and no. You've set up a false dichotomy, because neither half of your either/or question can be answered "yes."
As to the first part, under federal law, there is NO requirement that the person shipping a firearm to an FFL holder actually BE an FFL holder. In other words, private individuals are free to ship firearms interstate to FFL holders. Consequently, there is no requirement that a copy of an FFL be sent "with a firearm being transferred."
That said(tm), the FFL holder RECEIVING a firearm needs to log it in and include evidence of where it originated. Typically, that means a photocopy of the sender's driver's license, if the sender is not an FFL holder. If the sender is an FFL holder, however, it is common practice for the sender to send a copy of his or her FFL for the receiver's log book. It is not required by law, however.
As to the second part, there is also no requirement that an FFL holder send a "copy" of his FFL to someone who is sending him a firearm. There is a requirement that FFL holders who are shipping firearms interstate VERIFY that the receiving party is actually an FFL holder entitled to receive the shipment, and maintain a record of that verification. Up until about a year or so ago, that was typically done by obtaining a copy of the receiving party's FFL, signed in ink, for your logbook. With the advent of EZ Check, however, you can now obtain adequate verification by getting the receiving party's FFL number (part of it, actually) over the phone and running it through BATFE's online EZCheck system.
So nobody is actually legally obligated to send copies of FFL's to anyone.
