SEP Contribution to a closed business

Let’s say a business, called ABC, closed at the end of September 2019 and opened another business, called XYZ, in October 2019. If there are only two employee owners with W2’s of $80,000 from ABC and $40,000 from XYZ in 2019, are they allowed to contribute to SEP IRA’s to each company, i.e. $20,000 for ABC and $10,000 for XYZ, assuming there are enough K-1 incomes to cover the contributions? My key question is can you make SEP contribution to a company that has already been closed?

Thank you in advance for your help.