• If you pay your Social Security, Medicare, and income taxes withheld on a monthly deposit, you should make that deposit by this date for the November payment.

• If you withhold nonpayroll taxes and you deposit these taxes monthly, you should deposit the November payment by this date.

• If you operate on a cash basis, this is the last day that you can make any payments and charge the amount against expenses for the current tax year or collect income. If you operate on an accrual basis, this is the last day you can book revenue or expenses for the current tax year. Many businesses call throughout the month of December for last minute checks due so they can report income in the current tax year. They also check with vendors for missing invoices so that they can record expenses in the current tax year. If you work on an accrual basis, just billing the client for payments that are due will allow you to book that income in the current tax year. The same is true—provided you receive a written invoice—for payables that are due.

• If you want to deduct a Keogh plan contribution for the current tax year and have not yet set up the paperwork, you must establish the Keogh plan by this date in order to deduct that contribution.