Burden of proof
The duty to prove a fact; it usually falls on the person who makes the claim.
Definition
The burden of proof is the obligation to provide sufficient evidence to establish a fact in dispute. In civil cases in England and Wales it falls on the claimant and the standard is the balance of probabilities — more likely true than not. In criminal cases the prosecution carries the burden and must prove the case beyond reasonable doubt.
In practice
Gather and preserve your evidence from the first day of the dispute. The burden of proof means you must show the court more than the other side denies it.