I am writing to provide an explanation for the gap in my employment history as indicated in my mortgage application. I would suggest a few things to say in the letter.Explain what caused the employment gap, and be honest about it. You have employment gaps. Mortgage lenders might request a letter of explanation for various red flags that come up in underwriting. Learn how to write one, and download a template. I am writing to you in regards to the letter of explanation you have requested regarding my gap in employment. Here are our tips on writing a letter of explanation for credit inquiries. A letter of explanation is included in your mortgage application to help clarify inconsistencies or gaps in your financial records or credit history. The lender already knows, or at least suspects, an issue with the application.