The difference between a condition and a warranty in Insurance

The definitions of a condition and a warranty are very specific in the context of insurance law. 
A warranty can be a condition but a condition may not be a warranty.
Generally, a condition is an essential part of a contract, and if breached, the party that has been deprived is permitted to claim damages and even terminate the contract because the breach has in effect repudiated the contract. On the other hand, a warranty would not be considered a vital part of the contract. In the event that one of the parties to the contract is found to be in breach of the contract, he or she is at liberty to make a claim in damages but this does not mean that the party who did not breach the contract could terminate the contract. The meaning of these terms is reversed in insurance law.
 
Warranties play a greater part in insurance law than conditions. A warranty is a term of insurance contract that if the insured has breached, the insurer is no longer held to be liable as of the date of the breach. So a breach of a warranty would invalidate the insurance claim.
Warranties include promises, warranties of opinion and promissory warranties. Warranties as promises relates to facts that the insured agree to do or not do. Warranties of opinion are given based on information that the insured believes to be true to the best of his or her knowledge and belief. A breach of this warranty would occur if the insured knowingly gave false information to the insurer. Promissory warranties are based on future promises or continuing promises from completed proposal forms or within the body of the insurance policy.
Some conditions can be warranties but warranties may not always be conditions. The nature of conditions is quite complicated in insurance law; and includes condition precedents, mere conditions, promises and conditions precedent. The heading ‘Conditions’ is prominent in most insurance policies. In most cases, this term does not relate to the statements of fact or the risk covered within the insurance policy. They could in fact be warranties, collateral promises or stipulations.

It is important to distinguish between warranties and conditions for many reasons. For example, a typical condition of an insurance policy is that the insured must provide the insurer will all pertinent information about himself or herself. If the insured has failed to do so, the insured is in breach of his or her policy but the insurer is likely not to make a claim if the insurance company acquired this information from another source. On the other hand, warranties must be more strictly complied with for the policy to be valid.
Broadly speaking, there are two types of collateral terms which are considered conditions: promises or obligations imposed on the insured in relation to the claims procedure which are not considered fundamental to the validity of the contract; and conditions conferring rights on the insurer, which emphasis or reiterate the rights of the general law.
Lord Saville in the case, Hussain v. Brown (1996) made a useful observation about defining conditions and warranties:-
 

“In my judgment…there is no special principle of insurance law requiring answers in proposal forms to be read, prima facie or otherwise, as importing promises to the future. Whether or not they do depends on ordinary rules of construction, namely consideration of the words of the parties have used in the light of the context in which they have used them and ( where the words admit of more meaning) selection of that meaning which seems most closely to correspond with the presumed intentions of the parties.”
Warranties and conditions in insurance law are subject to interpretation of the language used, and the intention of the parties. When there has been a breach of a condition or warranty, the onus of proof is on the insurer to demonstrate that the breach has occurred and who is at fault.
 

Special thanks to: Ms. Trudy O. Glasgow is a practising attorney at the law firm Gordon, Gordon & Co., (and has also taught law at University level in the UK)*. http://www.thevoiceslu.com/features/2010/march/13_03_10/The_difference.htm