I'm considering the RFM69HCW 433MHz transceiver radio for use in some RFID-based equipment that we make in low volume. The RFM69HCW is available in 868MHz or 915Mhz as well but those frequencies are very close to the UHF frequencies that the RFID readers in our equipment use (902 to 928 MHz). I theorize that 433MHz, being very different in frequency from our UHF RFID radios is less likely to interfere (I don't have evidence to support this and would welcome any insight on the validity of my theory).
Assuming 433MHz does pose less of a risk of interference, I've been trying to find information about the regulations on this frequency in North America (we're only concerned with Canada and USA for now). I've seen 433Mhz described as "ITU American amateur with limitations". I can't find any clarification on what that really means and if it also pertains to Canada.
For some context the equipment we're considering it for is built in low volume and operated by our own staff. We don't expect to apply for certifications for it. Our concern is with breaking the law and with causing, or being affected by, interference with other people's radio communications.