A resignation letter is a formal notice from an employee to an employer announcing the intention to leave the job. It creates a written record of the date notice was given and the last working day, which protects both sides from later disputes over the notice period, final pay and handover.
In Malaysia, the notice period is normally set out in the employment contract or offer letter. Where the contract is silent, the Employment Act 1955 provides minimum notice periods that increase with the employee's length of service. As a rule of thumb, check your contract first; if you need to leave before the notice period ends, most contracts allow payment in lieu of notice or a shorter period by mutual agreement.
A good resignation letter is brief and professional. It should state the position held, the date of the letter, the notice period being given, the last working day, and thanks for the opportunities received. You are not obliged to give a reason; if you choose to, keep it short and positive. Avoid criticising the company or colleagues, as the letter stays on your personnel file and may affect future references.