Late P11D's

Hello

Client has signed P11D(b) but I will not receive it until Wednesday 07/07/10. No PAYE reference in place

I am intending to write to client attaching the various docs, together with the cheque for the class 1a NIC which the client will also be sending.

Will there be a penalty, or is the fact that I am sending the cheque before the due date enough to mitigate it?

Is there any other way to avoid the penalty, i.e filing online without a PAYE Ref? (Don't think that is possible)

Thanks in advance