Uninsured And Underinsured Motorist Cover Explained

Liability cover pays for harm a driver causes to others. Uninsured and underinsured motorist cover answers the opposite problem: harm caused to the policyholder by someone who cannot pay for it.

Two distinct gaps

Uninsured motorist cover applies where the at-fault driver had no insurance at all, or where the vehicle left the scene and cannot be identified.

Underinsured motorist cover applies where the at-fault driver was insured but carried limits too low to cover the injuries caused.

The second gap is the more common one, because minimum required limits in many jurisdictions have not kept pace with medical and repair costs.

How the underinsured calculation works

Wordings differ on whether the cover pays the difference between the two limits or pays up to its own limit after the other insurer's payment.

The difference is substantial. Under a reduction approach, cover equal to the other driver's limit produces nothing at all.

Because the structure is contractual rather than intuitive, comparing this coverage between insurers requires reading the wording rather than the limit.

Why hit-and-run claims sit here

An unidentified driver is treated as uninsured, since there is no policy to claim against, and the policyholder's own cover responds instead.

Many wordings require physical contact with the unidentified vehicle, or independent corroboration, to guard against claims where no other vehicle existed.

Prompt reporting to the police is usually a condition, and delay in reporting is a frequent ground for declining this class of claim.

Stacking and how limits combine

Where a household insures several vehicles, some jurisdictions permit the limits to be combined for a single accident, which multiplies the available cover.

Insurers often offer non-stacked versions at lower premium, and the election is usually made once and then forgotten.

Whether stacking is permitted, and whether an insurer may exclude it, is a matter of local regulation rather than a universal feature.

The claim is against your own insurer

This is the structural point that catches people out: the claim is made against the policyholder's own insurer, which then occupies an adversarial position.

The insurer is entitled to test causation, injury severity and the fault of the other driver in the same way any liability insurer would.

Availability, mandatory offers, stacking rules and limits vary by jurisdiction and change over time, so the policy wording and local requirements govern.