Sometimes when you are an employer, you might have happened to have made no wage or salary payments at all for a PAYE month such as the month from 6 December 2016 to 5 January 2017, in which case you must submit electronically an Employer Payment Summary as a NIL return by 19 January. This is too easy to overlook.
If you engage a local accountant and business adviser or a payroll bureau to do your wages, then this will be taken care of. In our case we keep a diary and do a batch of payrolls at about the same time each month. Our payroll files are bright yellow like the P30BC booklet so we do not overlook them.