401(k) Pay Checklist: October 1 Safe Harbor

You are deciding whether a 401(k) can carry founder pay before the safe harbor deadline. Employee deferrals, including an owner's, are available only from compensation earned after the deferral election is filed, not from paychecks already paid. ShareBuilder 401k's Safe Harbor 401(k) announcement sets October 1 as the deadline for a plan to take effect in the current year. Those two rules decide whether the plan can carry founder pay without adding burn.

October 1 is the cash gate

A new safe harbor 401(k) needs three months of operation in the plan year, which puts the effective date for a calendar-year business at October 1. If the plan starts later, the current-year deferral option closes. You can still build a plan, but the founder pay question changes. The business must decide whether to wait for the next year or accept a different design.

ShareBuilder 401k is running a special offer for businesses with employees to establish a first 401(k) plan while working toward the safe harbor deadline. The offer helps only if the plan can be live in time. Setup speed is the point. A special offer does not extend the limit.

The election date controls tax treatment

The owner 401(k) election is the second gate. A founder who waits until the end of the month may find the deferral period too narrow. The filing date controls the tax treatment.

If the safe harbor design is missed, the SECURE Act lets a plan add a nonelective safe harbor design retroactively for the year. That fix addresses the employer contribution side. It does not solve the owner deferral question. The distinction affects the bank balance.

The credit lowers setup cost, not the ongoing bill

The SECURE Act 2.0 startup tax credit can offset setup cost, with a maximum of $16,500. That number changes the math for a small company. It does not pay the ongoing cost. It does not replace the need for cash discipline.

Setup cost is only the first expense. Ongoing administration, recordkeeping, and employee communication can add up. A bootstrapper should ask for the full annual cost before choosing a plan. The credit should not be the only reason to adopt the plan.

SECURE 2.0 applies an automatic enrollment rule to new 401(k) plans created after December 29, 2022, beginning in 2025, with default rates starting at 3% to 10% and rising 1% per year until they reach 10%. A founder should explain the default before the first payroll. That conversation is part of the cost.

Run the four-question test before signing

A deferral is a cash decision as much as a tax decision. The money leaves the business as a contribution, even if the tax benefit comes later. A bootstrapped founder should compare the deferral to the next invoice, not to last year's profit. If the revenue is already committed to payroll, software, or debt, the deferral can feel like a hidden expense.

The slower choice is often the better choice. A smaller deferral that the company can fund without stress is safer than a large deferral that depends on a late invoice. Revisit the amount later if the revenue holds. The plan should follow the cash, not the tax idea.

Use the test before you sign anything. Each item is a yes/no check you can finish fast.

• Is the plan effective by October 1?
• Is the owner 401(k) election filed before the pay is earned?
• Can deferrals be funded from future revenue without breaking cash?
• Does the startup credit offset setup cost?

If all four answers are yes, adopt the plan and size the deferral to future revenue you expect. If one answer is no, wait for a cleaner setup or choose a smaller deferral that the revenue can cover.