The effect of a late (or non-payer) is two-fold: your business has spent time and money on the work,  now you have an expectation to collect payment at a certain time.

It is not only the bottom line of receiving payment but also the outlay and opportunity costs- together with your financial planning and budget.

Late payments thus throw you off and unfortunately your bills do not discriminate and do not slow down.

A good business is once that manages its collection rate well and makes sure that its book is easy recoverable and in line with its envisioned terms and conditions (ie if your terms are that you run your business cash on delivery then you must  stick to it, if your terms are payment on 30 days then stick to that etc).