The coordination usually comes down to possession dates written into both contracts, sometimes with a rent-back arrangement so the seller stays a short additional period after closing while the next home is ready. That takes planning before either property lists, not after an offer is already on the table.
A realistic equity number set early is what makes the timing work. If a home worth $500,000 carries a $100,000 mortgage, the $400,000 in equity is what has to stretch to cover the next place, so knowing that figure before listing avoids a rushed decision later.
Joel Dyck plans the sale and purchase side by side so a senior moves once. Get your hand-reviewed valuation from Joel Dyck.