Jim decided to sell his business because he wanted to retire. Through their lawyers, Mike agreed to buy Jim's business for $500,000. A certified cheque was specified as the method of payment for the sale. On the date fixed for closing the transaction, Mike's lawyer gave Jim's lawyer a certified cheque for $550,000, drawn in error. Jim did not really like Mike in the first place and wondered whether Mike would ruin his business legacy.

Describe whether Jim can keep the $50,000 extra, is obligated to return the $50,000, or can avoid the transaction altogether. Provide the legal reason(s). Hint: Performance of Contractual Obligations