Insurance companies earn investment profits on "float". Float, or available reserve, is the amount of money on hand at any given moment that an insurer has collected in insurance premiums but has not paid out in claims. Insurers start investing insurance premiums as soon as they are collected and continue to earn interest or other income on them until claims are paid out. The Association of British Insurers (gathering 400 insurance companies and 94% of UK insurance services) has almost 20% of the investments in the London Stock Exchange. In 2007, U.S. industry profits from float totaled $58 billion. In a 2009 letter to investors, Warren Buffett wrote, "we were paid $2.8 billion to hold our float in 2008."
An entity seeking to transfer risk (an individual, corporation, or association of any type, etc.) becomes the 'insured' party once risk is assumed by an 'insurer', the insuring party, by means of a contract, called an insurance policy. Generally, an insurance contract includes, at a minimum, the following elements: identification of participating parties (the insurer, the insured, the beneficiaries), the premium, the period of coverage, the particular loss event covered, the amount of coverage (i.e., the amount to be paid to the insured or beneficiary in the event of a loss), and exclusions (events not covered). An insured is thus said to be "indemnified" against the loss covered in the policy.
In managing the claims handling function, insurers seek to balance the elements of customer satisfaction, administrative handling expenses, and claims overpayment leakages. As part of this balancing act, fraudulent insurance practices are a major business risk that must be managed and overcome. Disputes between insurers and insureds over the validity of claims or claims handling practices occasionally escalate into litigation (see insurance bad faith).