Yes. per TCPA and US carrier guidelines, Businesses must have a user's consent before sending them a message. Businesses must also be able to provide a documented proof of consent when requested.
Businesses must also comply with any STOP request to their Toll-free number from the end-user and must immediately cease sending them messages.
If a user wants to resume receiving messages from a Business's Toll-free number to which they have previously sent a STOP message to, the user must first send an "unstop" MO message to the particular Toll-free number.