Pass the 9-5-6 Test
There are specific rules that apply to the payment of honorariums. Be sure you pass the 9-5-6 Test:
Honorariums can be paid to the following visa types: B-1, B-2, WB, WT, and J-1.
WB and WT visa waiver stamps are given to visitors from the following countries who complete an I-94 upon arrival: Andorra, Argentina, Australia, Austria, Belgium, Brunei, Denmark, Finland, France, Germany, Iceland, Ireland, Italy, Japan, Liechtenstein, Luxemburg, Monaco, Netherlands, New Zealand, Norway, Portugal, San Marino, Singapore, Slovenia, Spain, Sweden, Switzerland, United Kingdom, Uruguay.
If the country is not listed above then the prospective visitor should apply for and receive a B-1 or B-2 visa in order to travel to the United States.
NAFTA rules default Canadian visitors to B-1 or B2.