December 1 – Employers
During December, ask employees whose withholding allowances will be different in 2023 to fill out a new Form W4 or Form W4(SP).
December 15 – Social Security, Medicare and Withheld Income Tax
If the monthly deposit rule applies, deposit the tax for payments in November.
December 15 – Nonpayroll Withholding
If the monthly deposit rule applies, deposit the tax for payments in November.
December 15 – Corporations
The fourth installment of estimated tax for 2022 calendar year corporations is due.
December 31 – Caution! Last Day of the Year
If the actions you wish to take cannot be completed on the 31st or a single day, you should consider taking action earlier than December 31st.