FCC Part 15
also: Part 15B · Part 15C · FCC ID · SDoC · Class A vs Class B
US rules on radio-frequency emissions from electronics: Subpart B for unintentional radiators, Subpart C for intentional ones such as Wi-Fi and BLE.
Almost every electronic product sold in the US falls under 47 CFR Part 15. Subpart B covers unintentional radiators: digital devices that emit radio-frequency energy as a by-product of their clocks and processors. They are classed as Class A (commercial and industrial use) or Class B (residential use, with stricter limits), and most are authorized through a Supplier's Declaration of Conformity (SDoC) based on testing, without filing with the FCC.
Subpart C covers intentional radiators, products that transmit on purpose, such as Wi-Fi, Bluetooth, LoRa and other unlicensed radios. These require Certification through an FCC-recognized Telecommunication Certification Body (TCB) and receive an FCC ID that must be shown on the product label, or electronically where the rules allow.
Most connected products need both: Subpart C for the radio and Subpart B for the rest of the digital circuitry. A pre-certified radio module simplifies the Subpart C part but does not remove Subpart B testing of the complete product.
Founder takeaway
Decide whether your product is Class A or Class B, identify every intentional radiator, and budget for both Subpart B and Subpart C work.
sources
engineer review pending