Also, to enhance its enforceability, it is advisable to have the assignment agreement witnessed or notarized, depending on the jurisdiction's legal requirements. Additionally, maintaining a record of the executed contract is essential for future reference and as evidence of the assignment.
If you communicate clearly, then this is typically not an issue. This is because the seller has signed a legal and binding contract, which makes them obligated to fulfill the terms of the contract. You have every right to perform an assignment of contract when everything has been done legally.