Most lenders today will want to know every detail of your financial life. If something looks odd, or doesn’t make sense they will want to have some sort of explanation. This means that you will have to write letter explaining everything. For instance they may want to know why a credit card issuers pulled your credit three months ago when you were trying to apply for store credit, or why you changed jobs a few months ago or why you have moved from job to job over the last couple years. It’s best to write them and explain everything in full detail and move on. They do this simply to verify your financial stability and it is usually something that is requested from time to time.
As an example, when I was buying my first home, my lender called me three days before closing to let me know that my credit score had fallen to one point below the threshold for my interest rate, so I would either have to take an action that would improve my credit score immediately or accept a significantly higher interest rate. The solution required me to pay off one of my credit cards and fax proof of it to the lender -- not an impossible situation, but certainly a hassle when I was told it had to be done right away and I was at work.
Once you find a home you want to put an offer on, you have to obtain the actual mortgage loan. Apply for a loan with your chosen mortgage lender. Within three days of your application you should receive a loan estimate that includes closing costs, the interest rate, and the monthly amount you’ll pay for the principal, interest, insurance, and taxes. After that, it’s off to the underwriter, who will review all of your financial information and make the final call to approve or deny your loan.