While an agreement written on plain A4 paper with witnesses can be a starting point, its legal validity in future disputes hinges on several factors. For an agreement to be fully enforceable in court, it generally needs to be executed on stamp paper of the appropriate value, depending on the nature of the agreement. Furthermore, if the agreement falls under the purview of compulsory registration, it will hold no legal standing unless officially registered. Failing to adhere to these stamp duty and registration requirements can render the document inadmissible as evidence, potentially leading to significant penalties.