Three different things people run together
Termination. The contract ends going forward, through a route it provides for or by mutual agreement. What has been given so far usually stays settled.
Rescission. The contract falls away because the other side did not perform, and the parties return what they received.
Annulment. The contract is attacked because of a defect at the time it was made: mistake, fraud, dire necessity, lack of capacity.
The route and the consequences differ. So the first job is to establish which is yours, rather than sending a general letter saying you “are pulling out”.
The procedure matters
For rescission based on non-performance, a suitable period for performance normally has to be given first, in writing.
If that procedure is not followed, the rescission may not have the effect you expected, and you end up being the party in breach.
So do not write “I am rescinding the contract” on your own initiative before it has been checked what your particular case requires.
What gets returned
On rescission the parties return what they received. In practice the arguments start here: over use in the meantime, over improvements, over costs and over interest.
If you have paid a substantial sum, document every payment and its date. Bank transfers are the best evidence.
If the contract concerns property
There are additional requirements and consequences here, including as to registration. Do not take steps on your own before it has been checked, because with property, correcting a mistake is expensive.
If you signed under pressure or a misapprehension
Say so, even if it is uncomfortable. There are time limits for attacking a contract and they are not long, and silence is usually read as confirming it.
Related
Breach and penalties, consumer protection.
What I will need
The contract and its annexes. All payments. The correspondence, particularly where you made demands or received promises. If you have already sent a notice, bring exactly that.
This page provides general information and does not constitute legal advice on any specific case. Rights and deadlines depend on the facts and the applicable law.