3.4 Deposit Schedules, Lookback, and Penalties

Deposit Rules Are Cash Timing Rules

A payroll tax deposit moves money to the Treasury; a payroll tax return reports the liability. The two are related but not the same. The FPC exam frequently gives a fact pattern where the Form 941 can be prepared correctly, yet the employer still has a deposit penalty because cash moved late or under the wrong schedule.

For Form 941 employers, the deposit system generally covers withheld federal income tax plus both employee and employer shares of Social Security and Medicare. FUTA has its own quarterly accumulation rule and Form 940 reporting. Do not mix the two deposit systems just because both are federal payroll taxes.

Monthly vs. semiweekly schedule

IRS guidance says there are two primary deposit schedules for Form 941 taxes: monthly and semiweekly. The schedule is based on tax liability reported during the lookback period, not on how often the employer pays employees. For 2026 Form 941 deposit schedules, the lookback period is July 1, 2024 through June 30, 2025. If the employer reported $50,000 or less during the lookback period, it is generally a monthly schedule depositor. If it reported more than $50,000, it is generally semiweekly. New employers generally start as monthly depositors because pre-start lookback liability is treated as zero, unless the $100,000 next-day rule applies.

The words monthly and semiweekly describe the rule set, not the pay cycle. A semiweekly depositor that pays only once per month may still deposit only once for that month, but the due date is determined under the semiweekly payday rule. A monthly depositor with weekly payroll deposits all tax liabilities for the month by the 15th of the following month unless a special rule accelerates the deposit.

The $100,000 next-day rule

IRS Publication 15 says that if an employer accumulates $100,000 or more of employment taxes on any day during a monthly or semiweekly deposit period, the employer must deposit by the next business day. The threshold is measured within the relevant deposit period; amounts do not keep accumulating after the deposit period closes. Once the threshold is reached, the employer stops accumulating at the end of that day and starts a new accumulation the next day.

The rule can change the employer's future schedule. If a monthly schedule depositor reaches the $100,000 threshold during a deposit period, it becomes a semiweekly schedule depositor on the next day and remains semiweekly for at least the rest of that calendar year and the following calendar year. An exam scenario may describe a new employer with zero lookback liability that immediately runs a large bonus payroll. The correct answer is not simply monthly status; the next-day rule can override the starting schedule.

Deposit method and proof

Federal tax deposits must generally be made by electronic funds transfer. IRS Publication 15 identifies EFTPS, IRS Direct Pay, and the IRS business tax account as electronic options, with EFTPS providing an EFT trace number. For payroll operations, that trace number is audit evidence. A useful deposit control file includes the payroll register, liability summary by tax type, due-date calculation, deposit confirmation, and reconciliation to Form 941.

Accuracy rule, penalties, and trust fund risk

The deposit rule expects 100% of the liability by the due date, but IRS Publication 15 provides a limited accuracy safe harbor when the shortfall is no more than the greater of $100 or 2% of the amount required and the shortfall is paid by the required makeup date. Outside relief or reasonable-cause situations, deposit penalties may apply for late or insufficient deposits. The penalty severity increases as lateness increases, and using the return due date as a substitute for the deposit due date is a classic error.

Trust fund taxes deserve special attention. Federal income tax withholding and employee FICA are amounts withheld from employees for the government. If those amounts are not withheld, deposited, or paid, responsible persons can face the trust fund recovery penalty. For FPC purposes, this explains why payroll calendars, funding approvals, segregation of duties, and proof of deposit are not just administrative housekeeping. They protect employees, employers, and responsible payroll staff.

Compliance traps

• Do not choose monthly or semiweekly based on pay frequency or cash convenience.
• Do not wait until Form 941 is due if a deposit deadline came earlier.
• Do not combine liabilities from separate semiweekly deposit periods to decide whether the $100,000 rule applies.
• Do not assume a payroll service provider removes the employer's need to monitor deposits and confirmations.

Calendar example

Assume a semiweekly depositor pays wages on Friday, June 12, 2026. The payroll tax liability arises on the wage payment date, so the deposit is due the following Wednesday under the semiweekly rule. If the same employer accrues payroll expense on June 10 for accounting purposes, that accrual date does not control the federal deposit due date. The FPC answer follows the cash wage payment date.

Source checkpoints: IRS employment tax due dates, IRS Publication 15, IRS federal tax deposits overview, and PayrollOrg FPC outline.