Credit scores: what's the secret formula?

What's your credit score? And how do you end up with an excellent 970 or a dismal 655? For most people, the answer to both questions is that they have absolutely no idea. Yet when they come to apply for a mortgage, credit card or loan, suddenly the answers could mean the difference between buying the home of your dreams or languishing in rental property for the foreseeable future.

So it's worth understanding exactly what your score is all about.