Exchange
Exchange is only needed when buying a property, as until contracts have been “exchanged”, you or the person you are buying off, can still back out of the sale without significant financial or legal issues.
Once contracts have been signed and exchanged the sale is confirmed and it is more difficult for either party to back out without significant financial loss being incurred.
Completion
Completion usually happens a few days or weeks after the exchange in the case of a purchase and this is when the full amount of the sale is paid and you get the keys or usually within a month after you have received your offer in remortgage cases and your mortgage is transferred from your existing lender to us.