An exception to this general rule is that a contract prescribes or writes – for example, contracts. B consumer credit or consumer rental – can only be changed in writing. Implementing a change or change by the parties is often the best option. This is not only more appropriate when it is not a reflection, but there is also much greater certainty about the amendments that have been made and the parties that have accepted them. Changes to a construction contract are usually made by written agreement between the parties and are changes to the contractual provisions that do not include the scope of the work to be done. Since an amendment is a contract in itself, either consideration is required for the waiver to be effective or the amendment must be made as a single act. In addition, contracts (or variations) must be entered into for the sale of land by deed. In a recent Supreme Court decision[1] when one party claimed that an agency agreement had been amended to reduce the agent`s commission from 60% to 40%, one of the reasons the Court refused to implement the alleged amendment, namely that the agent did not receive consideration for the reduction of the commissions. In trade agreements, it is customary to include a provision that changes to a contract are null and void, unless they are written and signed by or on behalf of both parties. This is called the variation clause and is intended to avoid informal or involuntary oral variations. However, the common law allows for the amendment of a written contract by the mutual consent of both parties, either orally or in writing. This can complicate the position. As long as the law or the contract itself does not say otherwise, contractors can amend it by oral or written agreement.

Sometimes it is not only wise, but essential to change a contract in writing. Commercial contracts often contain a clause stating that an amendment is only valid if it is written and signed by all parties. This type of clause aims to strike a balance between flexibility and security. While it allows the parties to amend their agreement (and thus allow the parties to be flexible in reflecting developments and subsequent changes in practice), this means that the parties should always have a definitive record of the agreed terms (depending on the time) and, therefore, avoid any dispute over the terms and conditions governing their relationship.