Relief for Seasonal Businesses Act of 2021 This bill raises the annual numerical limit on H-2B (temporary nonagricultural workers) nonimmigrant visas and provides an exemption to this cap for certain applicants. Specifically, the bill raises the annual cap on such visas from 66,000 to 350,000. Furthermore, if a worker seeking an H-2B visa had been counted toward the annual cap in one of the three preceding fiscal years, that worker shall not be counted against the cap again.