A lease cancellation letter is a memo that you dispatch to your landlord when you have decided to move out of your current accommodation. It is necessary to inform the other party well in advance as in case of unawareness your lease will lock you in for another term.
Remember, mostly the property-owners do not demand a letter of lease termination but still it is better to play safe and inform them with a margin of 30 days. A well-written lease cancellation letter can help you to come out of any unforeseen trouble.
The language of this letter completely depends on the reason of leaving that property. If you are not satisfied with the condition of that apartment/ house then you will have an upper hand but if the departure is due to your personal reason then you should be more formal and polite.
The first paragraph should start with proper greetings and then inform other party about your decision. Give complete details of property in possession and the exact date when you moved in.
In next paragraph, add some courteous sentences and then give the reason of you vacating. Give your addressee the impression that you will take notice of his/her concerns.
In the end, provide your contact details to setup a date for a move-out inspection and then close your letter with proper greeting.