Two people buy the same coverage, with the same limits and the same deductible, from the same company, and pay different premiums. This looks unfair until you notice what is actually being priced. The insurer is not selling the words in the policy. It is selling to absorb a particular expected cost, and the words are identical while the expected cost is not.
A note on what this guide does not contain. Nowhere below will you find a figure telling you how much any factor moves a price, because the weights insurers assign are set in rate filings that vary by company and by state, and this site has no sourced figure it could stand behind. What follows is the structure: which categories of factor exist, what each one is standing in for, and why two people differ on them.
How a premium is assembled
Simplifying a great deal, a premium has to cover the expected cost of claims, the cost of handling them, the cost of running the company and selling the policy, a margin, and the cost of the reinsurance the insurer itself buys. Only the first of those varies much from person to person, and it is the product of two things: how likely a claim is, and how expensive it is likely to be when it happens.
Every rating factor is an attempt to estimate one of those two, and they are estimated from the experience of large groups rather than from anything about you individually. An insurer cannot know whether you will have a loss. It can know how a population resembling you has behaved, and that is what the price reflects.
The categories of factor
- What is being insured
- The characteristics of the thing itself. For a vehicle, its make, model, age, safety equipment, repair cost and how often that model is stolen or damaged. For a home, its age, construction materials, roof, wiring, plumbing, heating and square footage. For a business, what it does and what it owns. For an animal, its species, breed and age. These drive both how often a loss happens and how much it costs to put right.
- Where it is
- Location is one of the strongest factors in most property and auto coverage, and it is standing in for several separate things at once: weather and catastrophe exposure, crime, traffic density, the cost of local labor and materials, the availability of emergency services, and the local legal environment in which claims are settled. Two identical houses in different places face genuinely different expected costs.
- Who is covered
- The characteristics of the people the policy protects. Which of these an insurer may use is a matter of state law and varies by state, so the honest answer to whether a particular personal characteristic affects your price is that it depends where you live. Your state insurance department publishes what is permitted there.
- History and experience
- Prior claims, prior losses, driving record, and for a business, its loss experience and sometimes a formal experience modification. This is the factor most directly about you rather than about a group, and it is also why a small claim can cost more over time than it pays.
- The coverage choices themselves
- Limits, deductibles, valuation basis, optional coverages and endorsements. These are not risk factors, they are the amount of risk you are transferring, and they are the part you control directly.
- How the risk is used
- Usage changes exposure independently of everything else. How far a vehicle is driven and for what purpose, whether a home is occupied year round or rented out, whether a business operates from one site or many, how often someone travels and where.
- How you buy and how you pay
- Distribution and administration costs are real costs. Buying through an agent, buying direct, bundling several policies, paying in full rather than in installments, receiving documents electronically and staying with one insurer over time all appear in the price, usually in the form of discounts.
- The company’s own position
- This is the category people forget, and it explains most of why two quotes for the same risk differ. Each insurer has its own claims experience, its own view of which risks it wants, its own expense base, its own reinsurance cost and its own appetite in a given state and a given line. A risk one company is trying to grow is a risk another is trying to shed, and both of those show up as a price.
Why the same risk gets different prices from different companies
Because the rating plan is not a physical constant. Each company files its own rates with each state regulator, choosing which factors to use, how to group them and how much weight each carries. They are working from different books of business, so their estimates of the same risk legitimately differ. A company whose existing customers resemble you has better information about people like you and less reason to be cautious about pricing you.
This is why shopping is worth doing, and why the company that came out ahead for one person will not necessarily come out ahead for the next. It is also why a price that was competitive when you bought it can stop being competitive without anything about you changing.
What this means in practice
- Most of what determines your price is not adjustable in the short term. Location, construction, breed and age are what they are.
- The parts you do control are the coverage choices, the discounts you qualify for, and which company you ask. Those are where effort pays.
- A quote is only comparable to another quote for an identical specification, because changing any coverage choice changes the price for reasons that have nothing to do with the company.
- If a price seems wrong, ask which factors drove it. Insurers can tell you what information they used, and errors in that information are common and correctable.
- Which factors an insurer may lawfully use is regulated, and the regulator is your state insurance department. The NAIC directory lists the office for your state, and rate filings are public records in most states.
The underlying point is simple enough to state plainly. Identical coverage is not an identical promise, because the promise is worth whatever it is expected to cost to keep.