Form 941 is the federal quarterly payroll tax return. It reports total wages paid during the quarter, federal income tax withheld from employees, and Social Security and Medicare taxes. You report both the employee portion that you withheld from paychecks and the employer portion you contribute as a matching amount.

Federal quarterly deadlines are April 30 for Q1, July 31 for Q2, October 31 for Q3, and January 31 for Q4. These dates don’t move. Miss them and the IRS assesses penalties immediately, even if you deposited all taxes on time throughout the quarter.

Filing and depositing are different things. Most employers deposit payroll taxes more frequently than quarterly. Depending on your total tax liability, you’ll deposit either semi-weekly or monthly. Small employers with $2,500 or less in quarterly tax liability can pay with the return itself. Everyone else deposits on schedule throughout the quarter, then files Form 941 to reconcile what was deposited against what was owed.

In California, you also file quarterly with the Employment Development Department. Forms DE 9 and DE 9C report state disability insurance, unemployment insurance, employment training tax, and personal income tax withholding. These are due by the end of the month following each quarter. California runs on its own system completely separate from federal filings, so you’re managing two sets of requirements. A San Diego bookkeeper familiar with California payroll can help you navigate both federal and state obligations without missing anything.

Most payroll software handles both deposits and quarterly filings automatically. QuickBooks Payroll, Gusto, and similar services calculate withholdings, make deposits on schedule, and file returns without you having to track deadlines. If you’re doing it manually, use the IRS EFTPS system for federal payments and e-Services for Business through California EDD for state.

The most common mistake is confusing deposits with filings. Business owners make their deposits on time but forget to file the quarterly return. Months later they receive penalty notices wondering what went wrong. The quarterly return is required even if all deposits were made correctly and on time.

Keep records of everything. The IRS can audit payroll records going back several years. You need to be able to show every paycheck issued, every deposit made, and every quarterly return filed. Discrepancies between deposits and quarterly filings trigger notices that take time and effort to resolve.

If managing deposits, deadlines, and both federal and California requirements sounds overwhelming, consider payroll setup and training to get configured correctly from the start. The right system handles these filings automatically so you can focus on running your business instead of tracking tax deadlines.