You generally do not need to wait, as long as you filed an extension and you are still inside the extension period. In that situation we can usually proceed using your two most recent filed returns. Because the file is running well past your latest documented tax year, expect the lender to ask for a profit-and-loss statement covering the unfiled year showing income did not decline, plus a year-to-date P&L for the current year. If you qualify on the income from your filed returns and the P&Ls back them up, there is no reason to hold off. The one time filing first pays off: when the unfiled year is meaningfully stronger. Filing lets that higher income count. So compare both paths before you apply rather than assuming waiting is the safer route. Documentation requirements vary by program and by how far past your last filed return the application sits, so confirm the exact list with your lender up front.