Under the CARES Act of 2020, businesses may be eligible for the ERC if they had employees and operated a trade or business. This includes tax-exempt organizations. However, with limited exceptions, it does not apply to governments or their agencies and instrumentalities.
A small eligible employer for 2020 is an employer that had 100 or fewer full-time (30 hours per week or more) employees on average per month in 2019, and for 2021 had 500 or fewer full-time employees on average per month in 2019.
Your business may be eligible for the ERC if its operations were fully or partially suspended by governmental COVID-19 orders limiting commerce, travel or group meetings. Or, if you experienced significant declines in gross receipts during 2020 (50% or more versus 2019) or the first three quarters of 2021 (20% or more versus 2019).  If your business started to operate on or after February 15, 2020, it may qualify to claim the ERC for the third or fourth quarters of 2021 as a recovery startup business.