I am writing to provide an explanation for the gap in my employment history as indicated in my mortgage application. A letter of explanation can clarify your financial situation and get you one step closer to qualifying for a mortgage.Master the art of writing a winning letter of explanation for your mortgage application with our comprehensive guide. Explain what caused the employment gap, and be honest about it. There are lots of reasons why people aren't employed. 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. A letter of explanation is a brief document you can use to explain something, like a previous bankruptcy, in your financial or employment history.