If you have a dispute with your employer you can raise a grievance where you are still employed, or you can have a “without prejudice ” communication to try and negotiate a settlement. These types of communication do not go before the tribunal.
This template Letter before Claim helps you set out the legal and factual basis of your claim. It tells your employer to settle the matter or else you will proceed to the employment tribunal or court. It is suitable to use where you were fired or left the job before you could raise a formal grievance.