Some buyers can use an offer letter mortgage to qualify for a home loan before starting their new job. Here's how offer letter loans work.If you're going to the same job, an offer letter should be more than enough proof for income. Many lenders will approve you based on an offer letter and verification of employment from your future employer. An employment letter for mortgage is a document that confirms your current employment status, income, and job stability. To obtain a letter of employment for a mortgage, request one from your employer or HR department. Mortgage lenders conduct thorough employment verifications throughout the loan process. What is an offer letter loan? If you have an offer letter and haven't started the job yet, you can still be eligible to buy a home. Present a letter from your employer.