@omairi

You cannot take Payroll for the LLC members unless the LLC has elected to be treated as a Corporation.

Payroll deductions that are the employee's contribution Must Be Put into the 401(k) account. That is the fiduciary responsibility of the Employer that withheld or deducted from the employees. That is the Employees' money and the employer cannot keep it; that would be Theft.

For "employer only" you seem to be referring to a nonelective component.

And your question of Expense is complicated by the condition of "payroll for the LLC members." In general, the Employee's deduction is already in the employers Gross Wage expense. The Employee contribution isn't expense when you Send it in. You already have taken it from the employee and that is the same as paying Taxes, which is Liability, not expense, for purposes of understanding Cash Flow.