Dear Mr. Kelvin,
Thank you for your application for credit with our company.
We regret to inform you that we are unable to offer you credit at the present time. This is because of your lack of proper permanent premises from which you conduct your business. Our credit requirements are very strict, one being that we always like to know where our customers are. A post office box is not our idea of proper permanent premises. However we will be pleased to consider your application again if this requirement is met.
Meantime we can continue to do business as we have been doing all this time.