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).
Methods for transferring or distributing risk were practiced by Chinese and Babylonian traders as long ago as the 3rd and 2nd millennia BC, respectively. Chinese merchants travelling treacherous river rapids would redistribute their wares across many vessels to limit the loss due to any single vessel's capsizing. The Babylonians developed a system which was recorded in the famous Code of Hammurabi, c. 1750 BC, and practiced by early Mediterranean sailing merchants. If a merchant received a loan to fund his shipment, he would pay the lender an additional sum in exchange for the lender's guarantee to cancel the loan should the shipment be stolen, or lost at sea.
Business insurance can take a number of different forms, such as the various kinds of professional liability insurance, also called professional indemnity (PI), which are discussed below under that name; and the business owner's policy (BOP), which packages into one policy many of the kinds of coverage that a business owner needs, in a way analogous to how homeowners' insurance packages the coverages that a homeowner needs.
When insured parties experience a loss for a specified peril, the coverage entitles the policyholder to make a claim against the insurer for the covered amount of loss as specified by the policy. The fee paid by the insured to the insurer for assuming the risk is called the premium. Insurance premiums from many insureds are used to fund accounts reserved for later payment of claims – in theory for a relatively few claimants – and for overhead costs. So long as an insurer maintains adequate funds set aside for anticipated losses (called reserves), the remaining margin is an insurer's profit.
In the United States, the tax on interest income on life insurance policies and annuities is generally deferred. However, in some cases the benefit derived from tax deferral may be offset by a low return. This depends upon the insuring company, the type of policy and other variables (mortality, market return, etc.). Moreover, other income tax saving vehicles (e.g., IRAs, 401(k) plans, Roth IRAs) may be better alternatives for value accumulation.
In the United States, the underwriting loss of property and casualty insurance companies was $142.3 billion in the five years ending 2003. But overall profit for the same period was $68.4 billion, as the result of float. Some insurance industry insiders, most notably Hank Greenberg, do not believe that it is forever possible to sustain a profit from float without an underwriting profit as well, but this opinion is not universally held. Reliance on float for profit has led some industry experts to call insurance companies "investment companies that raise the money for their investments by selling insurance."