Yes. If your client’s ability to perform under a contract (i.e., close the transaction) is contingent upon the closing of another property, the Addendum for Sale of Other Property by Buyer (TAR 1908, TREC 10-6) should be made part of the contract. Otherwise, the buyer risks default under the contract if he fails to close because the sale of the other property doesn’t close. Default by the buyer could result in termination of the contract and the loss of earnest money. Alternatively, the seller could also take action to enforce specific performance or other remedies through the legal system, or both.