We're updating a long-form guide on buying a second home while renting out your first. Our article includes first-person experience from someone who did this, and we're layering in named expert insights to cover the financial, tax, and legal angles that readers consistently ask about on forums like BiggerPockets and Reddit. We need experts who handle these situations regularly. Questions (answer any or all): 1. When a borrower wants to keep their current home and buy a second one, how do lenders count projected rental income from the first property toward qualifying? Can you explain the 75% offset rule and what documentation (like Fannie Mae Form 1007) is involved? What catches people off guard? 2. What's the biggest tax mistake you see first-time landlords make when they convert their primary residence to a rental? We're especially interested in the Section 121 capital gains exclusion timeline — when should someone plan to sell vs. hold long-term, and what's the cost of missing that window? 3. Many homeowners debate forming an LLC for a single rental property. When does an LLC make sense and when is it overkill? 4. What compliance or legal requirements do first-time landlords often miss — the kind that can result in fines or liability exposure? 5. For someone locked into a sub-4% mortgage rate on their current home, how should they think about the rent vs. sell decision in a market where second-home rates are above 7%? Is there a simple breakeven framework you'd walk a client through?