May 15

Employers: Deposit Social Security, Medicare and withheld income taxes for April if the monthly deposit rule applies.

Employers: Deposit nonpayroll withheld income tax for April if the monthly deposit rule applies.

Calendar-year exempt organizations: File a 2023 information return (Form 990, Form 990-EZ or Form 990-PF) or file for an automatic six-month extension (Form 8868). Pay any tax due.

Calendar-year small exempt organizations (with gross receipts normally of $50,000 or less: File a 2023 e-Postcard (Form 990-N) if not filing Form 990 or Form 990-EZ.

June 10

Individuals: Report May tip income of $20 or more to employers (Form 4070).