Any individual who has had to purchase car insurance may well have discovered huge discrepancies in the various quotations they are asked by different insurance companies. This has historically always been the case to an extent, but even more so given the rise of cost comparison sites online. It is perfectly possible to go to one of the major sites, enter your details and obtain up to 50 or so different quotations. It is not uncommon for these quotations to be anywhere between 200 and 2000 percent different from top to bottom of the scale.

It is often assumed that all insurance companies assess risk in pretty much the same way. This is true to an extent, depending upon how much data they have, and what their experience of risk underwriting is. Different insurance companies will have different levels of expertise in certain geographical areas, regarding certain makes of car and certain individual age groups and demographics. This experience will influence their understanding of risk, and may differ widely from other insurance companies will have more on this experience in these areas.

Rating a risk is not simply a mathematical formula, although in theory this is what it is based on. Whilst an insurance company will assess a risk based on their own criteria, and then load it by a small margin to make it profitable, this is only half the story.

There has always been a theory and a practice as to how insurance companies rate risks. The theory is that they will evaluate a risk, essentially into a percentage figure, which is what they charge as a premium. In reality, it is also very much about what they can charge, or get away with, in order to win the business and make money out of it.

This has intensified hugely the transition to lots of car insurance being done online, where it is considerably easier for the insurance companies to link it to other types of insurance, and to various utility billing accounts, credit cards or loan financing. This means that insurance companies can make strategic alliances with other companies in order to obtain business which is to their mutual benefit.

Insurance companies will often undercut each other in a way that a lot of businesses will in order to attract customers, and hope that customer retention over time will allow them both to increase their premiums and keep the business without customers moving elsewhere. Whilst that is a fairly basic principle of how insurance companies work, it is much harder to do it online, it was much simpler by paper. It is very easy a customer to switch insurance companies nowadays, and this has certainly eroded a lot of the loyalty felt to companies previously.

The other important factor is that insurance companies make a lot of their profits from investing premiums, as opposed from pure underwriting profits. With most types of insurance, premiums are paid up front and claims paid much later on. With car insurance, the really big claims tend to be liability claims, which are notoriously difficult to settle, and normally take several years to agree upon.

This isn't necessarily insurancers dragging their feet, although this can happen. With liability claims, it often takes a very long time to really assess damage caused to an individual, and how that damage has impacted on their lives, and in what ways.

What this also means is that for that for a period of time the insurancer by and large will not have to settle a claim. They might make an interim payment, but that would normally be at their discretion. This means that  companies can hang onto the premiums for quite a long period of time, before any claims have to be paid. This allows them to earn significant investment income, which they can then use to offset their level of rating in order to attract the business that they need to.