Why incurred but not reported (IBNR) matters to a first-time founder
Claims often arrive after the event or develop over time, so reported claims alone understate an insurer’s expected obligations. IBNR estimates help set reserves, prices and capital. Founders of insurance businesses need qualified actuarial input because weak assumptions can make solvency and profitability appear better than they are.
Examples of incurred but not reported (IBNR)
An insurer closes March with £600,000 of reported claim estimates. Based on past reporting delays and claim development, its actuary estimates another £180,000 of IBNR. The company records the combined expected obligation, then updates the estimate as claims are reported and more evidence becomes available.
Common misunderstanding
IBNR is not a hidden pot of cash and does not mean every estimated claim will be paid. It is an uncertain accounting estimate of obligations, commonly including unreported claims and further development on reported claims depending on usage. Methods, terminology and regulatory requirements vary by reporting framework and jurisdiction.
When to use it
Use IBNR when measuring insurance claim liabilities, planning capital or analysing an insurer’s results. Document data, methods and uncertainty, and review estimates as experience emerges. A non-insurance business should not label ordinary unpaid invoices or general future expenses IBNR; those items follow different accounting concepts.