A seller using your purchase money to buy their next home is a normal chain, and you are in the safest seat in it. You close first. The seller then uses your proceeds to close on the home they are buying. The practical wrinkle is timing: after your closing, the seller's funds may need a day or two to wire to the other escrow or title company before their purchase can close and they can move. Build a small buffer into your expectations rather than assuming everyone funds and moves the same afternoon. A short rent-back, where the seller stays a few days after closing, is also completely normal. Same-day funding and recording is possible but varies by county. Some counties fund and record the same day, while in others a loan that funds one day does not record until the next. Your agent and escrow officer can tell you how your specific county handles it, so plan your move-in date with a little slack instead of counting on a same-day handoff.