Key Takeaways

  • The Law of Large Numbers allows insurers to predict losses accurately — more exposures = more predictable results
  • The Principle of Indemnity guarantees restoration to pre-loss position without profit — insureds cannot gain from insurance
  • Insurable interest must exist at BOTH policy inception AND time of loss for property insurance (unlike life insurance)
  • Subrogation allows insurers to recover payments from negligent third parties — 'stepping into the shoes' of the insured
  • Utmost Good Faith requires complete honesty from both parties — concealment or misrepresentation can void coverage
Last updated: December 2025

Principles of Insurance

Insurance operates on several fundamental principles that have been established through centuries of practice and legal precedent. Understanding these principles is essential for the P&C exam.

The Law of Large Numbers

Definition: As the number of observations increases, the average of the results converges toward the expected value.

In Plain English: The more people you insure, the more accurately you can predict how many will have losses.

How It Works

  • 1 homeowner: Impossible to predict if they'll have a fire
  • 100 homeowners: Still unpredictable for any individual
  • 1,000,000 homeowners: Can predict with high accuracy that approximately X% will have fires

Insurance Application

Pool SizePrediction Accuracy
100 policiesLow — actual losses vary wildly from expected
10,000 policiesModerate — closer to expected losses
1,000,000 policiesHigh — actual losses very close to predicted

Example:

  • 1,000 people each pay $1,000/year = $1,000,000 collected
  • Based on history, 90 people will need $10,000 each = $900,000 in claims
  • Insurer profit: $100,000
  • This works because of large numbers — with only 10 insureds, one unexpected loss could bankrupt the insurer

Principle of Indemnity

Definition: Insurance guarantees to restore the insured to their pre-loss financial position — no better, no worse.

Key Rules

  1. Payment is the lesser of:

    • Actual amount of loss, OR
    • Policy limit
  2. Insured cannot profit from a loss

  3. Compensation cannot exceed actual financial harm

Example

ScenarioResult
Car worth $10,000, damaged $3,000Insurer pays $3,000 (actual loss)
Car worth $10,000, total lossInsurer pays $10,000 (ACV)
Car insured for $15,000, worth $10,000, total lossInsurer pays $10,000 (can't exceed actual value)

Why This Matters: Indemnity prevents moral hazard — if people could profit from losses, they'd be tempted to cause them.


Insurable Interest

Definition: A financial stake in property or a person such that loss would cause financial harm to the interested party.

Critical Timing Rule

Insurance TypeWhen Interest Must Exist
Property & CasualtyAt policy inception AND at time of loss
Life InsuranceOnly at policy inception

Exam Alert: This timing difference is frequently tested. For P&C insurance, you need insurable interest at BOTH times!

Types of Insurable Interest

  • Ownership — You own the property
  • Secured creditor/Mortgagee — Bank has interest in mortgaged property
  • Bailee — Dry cleaner has interest in customer's clothes
  • Contract right — Buyer under purchase contract
  • Legal liability — Anyone legally responsible for property

Example: Why Timing Matters

Mark sells his house to Susan on Monday. Fire destroys the house on Tuesday before insurance is cancelled.

  • Mark cannot collect — he no longer has insurable interest at time of loss (he doesn't own it)
  • Susan cannot collect — she has no policy yet

Result: Neither party can recover. This illustrates why the timing requirement exists.


Subrogation

Definition: After paying a claim, the insurer has the right to "step into the shoes" of the insured and pursue recovery from any negligent third party.

How It Works

  1. You're injured in a car accident caused by another driver
  2. Your insurer pays your claim
  3. Your insurer then sues the at-fault driver to recover what they paid you
  4. You are "subrogated" — insurer takes your place in pursuing the claim

Priority of Recovery

When the negligent party pays, funds are distributed in this order:

  1. First: Insured recovers uninsured losses
  2. Second: Insurer recovers their claim payment
  3. Third: Remaining funds go toward insured's deductible

Why Subrogation Exists

  • Prevents insured from collecting twice (from insurer AND negligent party)
  • Holds negligent parties accountable
  • Helps keep insurance premiums lower
  • Reinforces the indemnity principle

Principle of Contribution

Definition: When multiple policies cover the same risk, each insurer pays a proportionate share.

Example

  • Policy A limit: $100,000
  • Policy B limit: $200,000
  • Total: $300,000
  • Loss: $60,000

Calculation:

  • Policy A pays: ($100,000 / $300,000) × $60,000 = $20,000
  • Policy B pays: ($200,000 / $300,000) × $60,000 = $40,000
  • Total: $60,000

Purpose: Prevents insured from profiting by collecting full amounts from multiple policies.


Utmost Good Faith

Definition: Both insurer and insured must be completely honest with each other.

Insurance contracts require a higher standard of honesty than typical contracts because the insurer relies heavily on information from the applicant.

Three Components

ComponentDefinitionExample
RepresentationStatements believed true to best of knowledge"I've had no accidents in 3 years"
WarrantyStrict promise that must be absolutely true"Smoke detectors are installed and operational"
ConcealmentFailure to disclose material informationNot mentioning a previous arson conviction

Consequences of Violation

If material information is false or concealed:

  • Insurer can void the contract
  • Insurer can deny claims
  • Even if premiums were paid in full

Material means information that would have affected the insurer's decision to issue the policy or set the premium.

Loading diagram...
The Five Core Insurance Principles
Loading diagram...
How Subrogation Works
Test Your Knowledge

For property insurance, when must insurable interest exist?

A
B
C
D
Test Your Knowledge

Your insurer pays your $10,000 auto damage claim after another driver hit you. The insurer then sues the at-fault driver. This is an example of:

A
B
C
D
Test Your Knowledge

An applicant fails to mention a previous arson conviction on their property insurance application. This is an example of:

A
B
C
D