That’s not quite true, in England the purchase of a house is not binding until the contract is signed and exchanged with a deposit, but completing the contract (paying the balance, handing over the keys) can be done at some agreed point in the future. In Scotland the difference is that when you make the offer to buy you include any conditions that need to be met (things that should they come up in conveyancing would cause you to withdraw). If the seller accepts the offer + the conditions you can only pull out under the conditions stated in the offer rather than for any reason you like. The process is still fundamentally: offer -> conyeancing -> contract -> completion