Deferrals not withheld

[Dazednconfused]

Employer's payroll company did not withhold deferrals for one payroll period. What is the correction required for one missed payroll? If the ER has to make up in QNEC has anyone ever experienced the payroll company paying for this?

Is it permissible to 'double up' the next payroll (and pay the lost earnings for the late deferral when calculated)? However, the 'double up' doesn't seem likely....

Thanks,