This is simply the difference between a conversation and hard copy documentation. A verbal or online disclosure of income, assets and down payment is all it takes to get prequalified. A preapproval, however, requires verification of your financial information. Ultimately, a preapproval takes a little more time and documentation, but it also carries more value with a prospective seller. Additionally, with a preapproval, you can be sure your lender and you view your income in the same way.