[David70]

https://www.irs.gov/retirement-plans...each%20payday.

Department of Labor rules require that the employer deposit deferrals to the trust as soon as the employer can; however, in no event can the deposit be later than the 15th business day of the following month. Remember that the rules about the 15th business day isn't a safe harbor for depositing deferrals; rather, that these rules set the maximum deadline. DOL provides a 7-business-day safe harbor rule for employee contributions to plans with fewer than 100 participants.