All solicitors use the Law Society 2009 Particulars and Conditions of Sale which set out the penalties for either if they fail to complete.
In addition, it is quite common these days to insert an additional clause in the contract saying that the entire transaction is based on the premise that if the purchasers lender does not issue the loan cheque, that the entire transaction can be set aside.
I've seen conditional contracts recently with a clause stating that if the entire transaction does not conclude by end December ( this is for the Mortgage Interest Relief benefits) it will be set aside.
Ultimately, these clauses depend on the relative positions of the parties and what makes most sense if there is a breach.
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